[barnabee]

I think they're missing the point, Twitter got the display name / username dichotomy right:

Display Name: what everyone sees next to your username, no guarantees that you don't change it every 5 minutes though...

username: something short you choose and change rarely, can be cool, memorable, fun, and quite creative, always unique

[Real Name: who cares, often necessary for work tools even though email ought to be enough]

[eugeniub]

Twitter has some problems too. People do change their username, and every time they do, all previous tweets mentioning them by @username lead to dead ends.

[vidarh]

If they do (I haven't verified if you're right) then that's an implementation issue. Twitters API returns rich information about every mention that shows they very well could store an association to the internal user id if they want to.

But it may very well be for good reason. E.g. lets say an account is taken over by someone who changes the account into something suitably offensive after obtaining a lot of mentions. It would seem that treating a change as basically "this is a new account now" is the safest alternative in some respects.

[netzone]

Just match the mentions to an ID instead of something that's not static.