It seems that the sensitive information leakage is something almost impossible to avoid when you have a pair of JIRA instances, internal and external, which are connected one to another.

Having them connected is clearly a business requirement for being able to cross link issues and to copy them from internal to external.

Even so it seems that internal activity information goes to the public instance freely when you connected them.

So far Atlassian support recommended to disable the activity feed plugin, but this change is not persisitent between service restarts not between service upgrades.

We do not a configurable option that is persistent like we already have the parameters for disabling email in JAVA_OPTS.