Outside of its terms of service agreement, Twitter is lawless. You can pretty much do whatever you want short of pretending to be a fictional Sesame Street character and talking shit about a Republican presidential nominee. That said, there are some people who push the boundaries of what's acceptable. These people are douchebags. We know 'em, you know 'em. There's a myriad of things these people do on Twitter that makes your skin crawl. For now we only picked 10. If you recognize any of these signs in yourself, well, it's time for you to do like MJ said and make a change.