I'm afraid the hacker situation is getting worse at this point. Two more MLP groups have been affected by this group, having most, if not all, of their work deleted.
The groups in question are ProtectPonyPrincess and LaurenFaustFans. The latter group wasn't even devoted to MLP, but merely had an MLP folder among all the other Faust-related stuff they had, and still they were a target.
To those among my members who run other MLP groups, I cannot stress enough how important it is for us to keep a sharp eye out for these people.
As a general rule, I allow no administrators to this group except for myself, but for those who do allow contributors and co-founders and such, I strongly reccommend that, until this issue is sorted, no administrative positions should be given to new applicants.
Let's hope this problem is resolved soon.