Scrub personal user info when disabling a user

No I think it's fine if we don't consider the user's login to be personal information. Since crc32 isn't a cryptographic hash it doesn't requite a lot of computational power to go from crc32 hash -> plaintext login (it seems even less than md5 or something like that). If we're fine with people who have access to our database having that ability, I'm fine with that. Although it does raise the question about whether we should even hash deleted logins in the first place? 

I found this [SO Question](http://stackoverflow.com/questions/14210298/probability-of-collision-crc32) about CRC collisions. It looks like CRC32, but not be good enough if we have any number of deleted users.