I'm siding with geius on this one. To the extent that no money changed hands and Steve wasn't paying them to use the celtics usename, then I think Twitter can do whatever they want whenever they want.

It may not be good karma for them to take the names without warning, but Twitter's job is to pay the bills and keep the lights on, not turn down good exposure (and perhaps some coin) to keep one guy happy who didn't have a true right to the name in the first place.

Perhaps they are getting some cash from the Celtics to use the name. So what? If you're one of the tens of thousands of people like Steve that are using Twitter for free to promote a business, then Twitter getting some cash to pay the bills another month is only a good thing.