Suppress Dashboard Gadgets for specific users/groups

In case of collaboration with customers via JIRA, it would be very helpful to extend JIRA's rights management to Dashboard Gadgets. For example, it is possible for a customer to add the Group Timesheet Gadget and display the worklog summary of any group he selects (even, when he is not member of that group).
As a JIRA Admin, I would like to manage the availabilty of Gadgets per Group/Role, so that confidential information can be kept inside our organization.