Twitter: home of open discussion, honest opinions... and thousands of people being outrageously rude and abusive, particularly to celebrities. If you look at David Camerons Twitter, for example, whether you support him or not its quite surprising just how much Twitter vitriol that he attracts. From calls of Panface, Moonface, Pieface, and other observations around how his head looks like a particularly shiny egg with a wig on it, to simple, expletive-filled dedications (w*nker seems to be a particularly popular thing to tweet at the current leader of the UK), Camerons Twitter account is a perfect example of how unflinching Twitter critics can be. Unfortunately for Cameron, he (or at least, his social media team) probably arent allowed to respond with snappy comebacks, or even your mum jokes. Its not just troll-hunting though: someone of the biggest and best celebrity feuds have made their way onto Twitter. Perez Hilton, Amanda Bynes, Alec Baldwin, and, well, usually Perez Hilton again, have had high profile and hilarious Twitter sparring matches. As an online playground it definitely attracts more punch-ups than not, and behind a computer screen people tend to be more outlandish (and hilarious) with their insults than not. This article has tried to stay within the last year or so to avoid repetition, but not to worry: we've still included some classics.