Justin Bieber Username: @justinbieber Followers: 106 million The Canadian pop star, who joined the social media site in March 2009, hasn't been posting much lately, except for tweets about his music and retweets showing his support for the March For Our Lives movement. If you're keen on getting your daily Bieber fever, you'll have more luck surfing the "Sorry" artist's Instagram page. Image Source: Getty / Stuart Franklin