Is it a good idea to let your users change their usernames? [closed]

Question

I'm back and forth on the idea of letting the users on my site change their usernames, which would be displayed through out the site. On one side I want to give the users flexibility. But on the other, I don't want them to use this feature as a way to hide if they do something unwanted on the site. I know SO & Twitter lets you change your display name. Whats keeping someone from behaving bad on the site and then changing their name so they can continue behaving bad?

I need feed back on the pro's and con's. Thanks!

Update: To clear things up a bit. I'm not using the user name as the primary internal account ID. Each user gets a unique number. My question is not really about my system tracking the user its about how other users will be able to track each other.

If userA knows that userB is doing something bad and then userB changes his name to userC. Then userA will no longer know who he is.

Answer 1

What do you mean with "do something bad and then change their name"? If you're implying that users can post content, for instance, with their name attached, and then change their name and the name attached to their posts won't change as well, then I think you need to reconsider your (database) architecture and ensure that a username is a single point of reference and all representations of that username change when someone changes their username.

Edit: OK, sorry for misunderstanding. But if it's the case that you have a single point of reference, then changing your username is irrelevant to the problem. Let's say my username is Foo and I troll some thread somewhere, then change my name to Bar. As long as people can see what I've posted (eg. a post history page), then it doesn't matter whether I used to be called Foo or not, Bar is associated now with posts made before that were troll material. So perhaps you just need to create transparency, by making something like a post history overview on users' profiles? :)

Answer 2

If the issue of impersonating someone or "cheating" is a factor you could always do ALA eBay and display an icon next to someone who changed their username in the past 30 days.

Depending on the case you can keep an history and display it if required.

If you do that make sure that previous usernames are not recycled for new users.