i think they tried steel wool too and it still worked too.
on the subject of backups at the moment they are only playable on hacked dev units, but if you head over to read the dev chats they are making some really great progress lately. Backups at the present moment arent that important to have as not only are they not usuable but some of them are quite large as well.
correct me if im wrong but... the first Bluray discs didnt have a scratch resistant and were held in a PSP's UMD style casing, but then TDK came along and made the first patented the protective layer... i believe it uses diamond-like material (and we all know diamonds are the hardest substance on earth)
correct ME if i'm wrong but if it was coated with a diamond like substance then it would be really hard to break... and as we all know, the disks snap really easily.
If it were indeed a "diamond-like" surface coat, my wife would be wearing my BRay discs on her fingers!!!