Lady Gaga joined Twitter way back in 2008, and it?s taken until now to set a new record for the social networking site. Lady Gaga has become the first Twitter user to reach 20 million followers. She has surpassed Justin Bieber, who is trailing behind with 18.1 million followers. Since overtaking Britney Spears as the most-followed person on the website in August 2010, Lady Gaga has held onto the top spot. And Gaga is way ahead of her fellow singers Katy Perry, who has 15.5 million followers, as well as Shakira and Rihanna, who both have about 14.5 million. Gaga uses the account to interact with her supporters, who she refers to as Little Monsters, but she actually hasn't tweeted since March 3 Just so you know, Gaga has eight million fans on Facebook and more than 800-thousand 'circles' on Google+.