"getPermissionsForUser" Remote method cannot be used to retrieve anonymous user permissions

yeah-yeah:~ jclark$ curl -v --data '["DS", ""]' -u admin:admin -H "Content-Type: application/json" http://localhost:8080/confluence/rpc/json-rpc/confluenceservice-v2/getPermissionsForUser?os_authType=basic

* About to connect() to localhost port 8080 (#0)
*   Trying ::1...
* connected
* Connected to localhost (::1) port 8080 (#0)
* Server auth using Basic with user 'admin'
> POST /confluence/rpc/json-rpc/confluenceservice-v2/getPermissionsForUser?os_authType=basic HTTP/1.1
> Authorization: Basic YWRtaW46YWRtaW4=
> User-Agent: curl/7.24.0 (x86_64-apple-darwin12.0) libcurl/7.24.0 OpenSSL/0.9.8r zlib/1.2.5
> Host: localhost:8080
> Accept: */*
> Content-Type: application/json
> Content-Length: 10
>
* upload completely sent off: 10 out of 10 bytes
< HTTP/1.1 200 OK
< Server: Apache-Coyote/1.1
< Set-Cookie: JSESSIONID=28F2CDD84892C02A575EB66E36B3383B; Path=/
< X-Seraph-LoginReason: OK
< X-AUSERNAME: admin
< Content-Type: application/json
< Content-Length: 27
< Date: Thu, 01 Aug 2013 18:27:01 GMT
<
* Connection #0 to host localhost left intact
["view","modify","comment"]* Closing connection #0

* About to connect() to localhost port 8080 (#0)
*   Trying ::1...
* connected
* Connected to localhost (::1) port 8080 (#0)
* Server auth using Basic with user 'admin'
> POST /confluence/rpc/json-rpc/confluenceservice-v2/getPermissionsForUser?os_authType=basic HTTP/1.1
> Authorization: Basic YWRtaW46YWRtaW4=
> User-Agent: curl/7.24.0 (x86_64-apple-darwin12.0) libcurl/7.24.0 OpenSSL/0.9.8r zlib/1.2.5
> Host: localhost:8080
> Accept: */*
> Content-Type: application/json
> Content-Length: 10
>
* upload completely sent off: 10 out of 10 bytes
< HTTP/1.1 200 OK
< Server: Apache-Coyote/1.1
< Set-Cookie: JSESSIONID=7906D198CB4D84E48FCE0BB50B7F529B; Path=/
< X-Seraph-LoginReason: OK
< X-AUSERNAME: admin
< Content-Type: application/json
< Transfer-Encoding: chunked
< Date: Thu, 01 Aug 2013 18:35:46 GMT
<
{"jsonrpc":"2.0","id":null,"error":{"message":"The application was unable to serve your request: com.atlassian.confluence.rpc.RemoteException: No user with the name '' exists.","data":"com.atlassian.confluence.rpc.RemoteException: No user with the name '' exists.\ncom.atlassian.confluence.rpc.RemoteException: No user with the name '' exists.\n\tat com.atlassian.confluence.rpc.soap.services.SpacesSoapService.getPermissions(SpacesSoapService.java:173)\n\tat com.atlassian.confluence.rpc.soap.XhtmlSoapService.getPermissionsForUser(XhtmlSoapService.java:191)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:606)\n\tat org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)\n\tat org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)\n\tat org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)\n\tat com.atlassian.spring.interceptors.SpringProfilingInterceptor.invoke(SpringProfilingInterceptor.java:16)\n\tat org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)\n\tat org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)\n\tat org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)\n\tat org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)\n\tat com.sun.proxy.$Proxy1618.getPermissionsForUser(Unknown Source)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)\n\tat java.lang.reflect.Method.invoke(Method.java:606)\n\tat com.atlassian.rpc.jsonrpc.SoapModuleMethodMapper.call(SoapModuleMethodMapper.java:122)\n\tat com.atlassian.voorhees.JsonRpcHandler.executeMethod(JsonRpcHandler.java:235)\n\tat com.atlassian.voorhees.JsonRpcHandler.process(JsonRpcHandler.java:83)\n\tat com.atlassian.rpc.jsonrpc.JsonRpcFilter.doFilter(JsonRpcFilter.java:76)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.plugin.remotable.plugin.module.permission.ApiScopingFilter.doFilter(ApiScopingFilter.java:63)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.prettyurls.filter.PrettyUrlsCombinedMatchDispatcherFilter.doFilter(PrettyUrlsCombinedMatchDispatcherFilter.java:61)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.core.filters.ServletContextThreadLocalFilter.doFilter(ServletContextThreadLocalFilter.java:21)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.util.LoggingContextFilter.doFilter(LoggingContextFilter.java:40)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.util.UserNameHeaderFilter.doFilter(UserNameHeaderFilter.java:26)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:211)\n\tat com.atlassian.confluence.web.filter.ConfluenceSecurityFilter.doFilter(ConfluenceSecurityFilter.java:28)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.web.filter.ThreadLocalCacheFilter.doFilter(ThreadLocalCacheFilter.java:22)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.security.auth.trustedapps.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:98)\n\tat com.atlassian.confluence.util.AbstractBootstrapHotSwappingFilter.doFilter(AbstractBootstrapHotSwappingFilter.java:30)\n\tat com.atlassian.confluence.util.AbstractBootstrapHotSwappingFilter$SwapOnBootstrapFilter.doFilter(AbstractBootstrapHotSwappingFilter.java:55)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat com.atlassian.confluence.util.AbstractBootstrapHotSwappingFilter.doFilter(AbstractBootstrapHotSwappingFilter.java:30)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.seraph.filter.BaseLoginFilter.doFilter(BaseLoginFilter.java:150)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:46)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.oauth.serviceprovider.internal.servlet.OAuthFilter.doFilter(OAuthFilter.java:55)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.prettyurls.filter.PrettyUrlsCombinedMatchDispatcherFilter.doFilter(PrettyUrlsCombinedMatchDispatcherFilter.java:61)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.util.ClusterHeaderFilter.doFilter(ClusterHeaderFilter.java:37)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:99)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.gzipfilter.GzipFilter.doFilterInternal(GzipFilter.java:80)\n\tat com.atlassian.gzipfilter.GzipFilter.doFilter(GzipFilter.java:51)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.core.filters.cache.AbstractCachingFilter.doFilter(AbstractCachingFilter.java:33)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:46)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.plugin.remotable.plugin.module.oauth.OAuth2LOFilter.doFilter(OAuth2LOFilter.java:81)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.plugin.remotable.host.common.service.http.bigpipe.BigPipeRequestIdFilter.doFilter(BigPipeRequestIdFilter.java:33)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.prettyurls.filter.PrettyUrlsCombinedMatchDispatcherFilter.doFilter(PrettyUrlsCombinedMatchDispatcherFilter.java:61)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter$1.doFilter(DelegatingPluginFilter.java:66)\n\tat com.atlassian.confluence.extra.webdav.servlet.filter.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:43)\n\tat com.atlassian.plugin.servlet.filter.DelegatingPluginFilter.doFilter(DelegatingPluginFilter.java:74)\n\tat com.atlassian.plugin.servlet.filter.IteratingFilterChain.doFilter(IteratingFilterChain.java:42)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:77)\n\tat com.atlassian.plugin.servlet.filter.ServletFilterModuleContainerFilter.doFilter(ServletFilterModuleContainerFilter.java:63)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.web.filter.validateparam.RequestParamValidationFilter.doFilter(RequestParamValidationFilter.java:58)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doF* Connection #0 to host localhost left intact
ilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.web.filter.TranslationModeFilter.doFilter(TranslationModeFilter.java:43)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.plugin.servlet.filter.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:71)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.web.filter.LanguageExtractionFilter.doFilter(LanguageExtractionFilter.java:53)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.util.RequestCacheThreadLocalFilter.doFilter(RequestCacheThreadLocalFilter.java:25)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.web.filter.DebugFilter.doFilter(DebugFilter.java:50)\n\tat com.atlassian.core.filters.AbstractHttpFilter.doFilter(AbstractHttpFilter.java:31)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.core.filters.HeaderSanitisingFilter.doFilter(HeaderSanitisingFilter.java:44)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat com.atlassian.confluence.servlet.FourOhFourErrorLoggingFilter.doFilter(FourOhFourErrorLoggingFilter.java:65)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)\n\tat org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:615)\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)\n\tat org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)\n\tat org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)\n\tat org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)\n\tat java.lang.Thread.run(Thread.java:724)\n","code":500}}* Closing connection #0