Lady Gaga has become the first Twitter user to reach 10 million followers, beating Justin Bieber to the milestone, despite Bieber having been first to reach nine million. Gaga posted a celebratory TwitPic tof herself waving to announce the news: “10MillionMonsters! I’m speechless, we did it! Its an illness how I love you. Leaving London smiling.” Now, it’s worth noting that Lady Gaga has more than 34 million fans on Facebook, but as AllTwitter points out, Facebook has more than three times the users of Twitter, so the numbers are equivalent. It’s enough to make you nostalgic – it was only spring of 2009 when we were speculating on whether Britney Spears would beat Ashton Kutcher to become the first Twitter user with one million followers.