XF 1.5 private thread creation, is there a way to see this as non-permissions?

[borgqueenx]

We have a pretty bad stalker that is terrorising our website and he apparantly knew the moment a thread was created in a private forum for specific usergroups only. I do not believe any account is compromised because else he would have used those accounts for bad things.

 

[Paul B]

Unless there is an add-on involved or a compromised account, this person won't have access.

 

[borgqueenx]

maybe there is a security flaw in an add-on then, we use quite alot.
thanks anyway. sigh.