A viral marketing attempt? Some fans (or possibly only one) with too much time on their hands? Either way, it's entertaining. Multiple characters from the Batman series and other related forms of media have popped up on Twitter. Sci-Fi blog I09 theorizes that it could be a marketing attempt, and a hint at an early release of "The Dark Night" DVD. Characters such as The Joker, The Riddler, Rachel Dawes, Harvey Dent, Two Face, James Gordon, Bruce Wayne, and... Gotham Cable News have accounts, and new ones are popping up every so often. So join up and follow them if you wish, whether it be for The Joker's sadistic humor, or The Riddler's interesting riddles. Profile List The Joker The Riddler Two Face Harley Quinn Poison Ivy Miranda Dent Lucious Fox Scarecrow Gotham PD Rachel Dawes Harvey Dent James Gordon Barbara Gordon Bruce Wayne Gotham Cable News Another Gotham PD, but with a link to a viral marketing site? Also, Hannibal Lector?
This is probably just a coincidental occurrence--so many people use twitter that I would be surprised if these names didn't pop up and them claiming that they are these characters. I doubt that people hadn't heard these names before and thought why not?