Just a query that I came across when was searching some answers. The OP in the following Link is greyed out. Any particular reasons. I cannot even click on that and visit his profile.
4The user has been deleted.– MysticialFeb 20, 2014 at 0:21
Any particular reasons???– JatinFeb 20, 2014 at 0:22
yep, read up - meta.stackexchange.com/questions/126470/…– CaffeinatedFeb 20, 2014 at 0:29
1@Jatin we can't know why specific user was deleted. Many times people ask for their account to be deleted for their own personal reasons. Sometimes users get angry at something and rage quit, destroying their content and being stopped by deleting the account. But bottom line, it doesn't really matter.– Shadow Wizard Strikes BackFeb 20, 2014 at 9:45
This user was deleted before they anonymized deleted user names. At that time, all user deletions were done by a developer (more than likely because they were fairly uncommon). Now with the spammers and a vastly larger user base, things have become a little more standardized.
@Wont describes it more in detail, but it basically breaks to "There are two options: Delete and Destroy." These two options include either having the user name anonymized and the content remains, or having everything completely removed.