Tweets are copyrightable:
Let’s face it: coming up with a grade-A tweet isn’t easy. That’s why some people just copy good tweets from other people and act like they came up with the 140-character witticism on their own. This has been going on since the beginning of Twitter.
It now appears Twitter is using its legal authority to crack down on these tweet-stealers. A number of tweets have been deleted on copyright grounds for apparently stealing a bad joke.
Don’t steal. Remix.