Bullying may be the most pressing issue that Twitter is fighting at the moment, but a close second is… joke theft? That’s what I can gather from the company’s decision to start taking down a number of tweets that have been reported as being stolen, with the person originally posting the tweet being referred to as a copyright holder. Twitter hasn’t been specific about what it considers copyright infringement when it comes to jokes so, true to their nature, Twitter users have been testing the limits themselves.