The social network currently has 271 million active users but, according to a new filing with the Security and Exchange Commission, over 8% of them arent operated by humans. One of Twitters big selling points, whether it be to music fans, grass roots political activists, sports obsessives, movie buffs or journalists, is that it breaks down the barriers between you and the person or the subject that most interests or excites you. Why turn to traditional forms of media to keep track of what, say, Justin Bieber is up to, when you can follow and converse with him directly, 140 characters at a time?