Although people are always hesitant to say the name, I actually think you're thinking of Redacted. There's a whole website and IRC room prepping for the entrance exam. Unfortunately, the site is just as joyless as the exam process would lead you to suspect. The top discussion in /r/trackers right now is about exactly that.

That's the one. Although the interview was mostly to make sure you knew the basics of how audio files worked and why people on the site cared about upholding their quality: nothing an hour of studying couldn't prepare you for.

The database of various rare releases, artist graphs, user collages, etc. were the biggest loss.

Thanks. I never really had the patience to manage ratios and survive on private trackers, and fishing for invites and passing an interview to get into the secret treehouse was too much for me.

Too late for that of course, but couldn't that data have been stored somewhere away from the questionably legal stuff?