Tweets are probably not copyrightable, but could be. This doesn’t mean tweeps cannot, or do not, steal your tweets and rebrand then as their own.
One way to find those tweet thieves is to use the Twitter search feature. Another, much simpler, way is to use a little web app: who stole my tweet.
The web app not only tells you the people who have stolen your tweets (to the right of your tweets,), but also the people you have copied the tweets from (to the left of your tweets).
To use it, simply enter your Twitter username and hit Go. The app will analyse your last 50 tweets. To analyse more, you will need to pay. A tweet will be defined ‘stolen’ if it has a similar content to one of your tweets without mentioning your twittername.
However, the app doesn’t analyses all the last 50 tweets. All tweets with mentions and all tweets with less than 16 symbols are excluded.
As someone who’s had my Twitter content stolen, I appreciate this. I don’t think it goes far enough, but I guess I could pay for that, if I chose to. I’ve had tweets and pictures stolen on Twitter, and think there should be a report button, as well. I doubt Twitter would follow up and go as far as warning or suspending the account, but that’s what should happen. If a man is only as good as his word, what does that say when he steals those words?