When you logon to StudiVZ, you get the following message:
We have the justified suspicion that somebody has tried to get access to StudiVZ. Therefore you current password is not valid anymore. To create a new password, please provide your emailadress below. You then get a link to create your new password. We apologize and thank for your understanding.
Don Alphonso suspects that they only want to clean their database. In any case, SchülerVZ is still working. The press release can be found at Robert Basic. The first one that discovered the bug was Andreas Dittes.