Katy Perry is having a good week! She just released her new album 'Witness,' she's on tour, and she just surpassed Justin Bieber and Barack Obama as the most popular person on Twitter. Miss Perry has a whopping 100 million followers! Bieber comes in at 96.7 million while Obama's follower count is at 90.8 million. Perry is used to breaking records, having the most viral video, 'Bon Appetit,' on YouTube in a single day. Go Katy!