Most (if not all) collaboration applications allow posting of a profile, with personal information. Since this information is shared only among the group members, some people feel safe in divulging more personal information than they really should.
Keep in mind, though, that you may not have control over who is a part of the collaborative space. On a work application it makes sense to keep it professional, but users seem to feel more freedom on sites such as Ryze or even Linked In. These are professional networking sites where some users have posted suggestive photos of themselves, included enough information in their profile or in forum posts that they could be found easily in the real world.
We need to monitor our children's computer use, but we need to monitor our own as well.
