I've seen other people's posts being manipulated (and it's not any of us either).
And still others had their groups gone missing (update: being restored).
End of May into June we've had several recent hack attempts.
None of them are as severe as last year's hack.
Stay tuned we're very aware of the situation and are working on it.
As a security measure, I would recommend that you folks go into your user profiles and change your YNC account's password. I doubt that anyone's account will be lost but just do it.