> How would you disallow them to use your name or identifying pictures ?

By making it against the TOS of the site, and banning profiles that do it.

> probably illegal ... not providing exact personal information.

Presumably it's a profile about you, but it's not a profile impersonating you. They don't sign up using your name/birthdate/et al; they have their own account, which they use to fill in the details of your profile.

To be clearer: the concept isn't really that you're filling out someone else's profile. Instead, it's more like (exactly like) a "review" site--friends giving "product reviews" of friends, talking about how you should "buy" this friend or that. They just appear without attribution, conglomerated into a "consensus profile" of "what others think about this person." I imagine it's very clear that the person themselves didn't make the profile, any more than hockeyfan3392 on Amazon made the Macbook his review is attached to.