If you are not a member of a workroom, you should not be able to see it. Current behaviour is to display an 'empty' form if you click on a workroom that you are not a member of.
(In our tests, the user was NOT an anonymous user).
Hello Mark!
This problem should be fixed when we fix the following issue:
Issue #34136 - The workroom does not clear access rights when creating it's folders and pages