Check out his trail of tweets on his twitter  

via usmagazine.com After Justin Bieber kept his fans waiting before taking the stage at London's O2 Arena on Monday, March 4, the 19-year-old singer apologized to concertgoers in a series of Twitter posts March 5.

"Last night I was scheduled after three opening acts to go on stage at 9:35, not 8:30, but because of some technical issues I got on at 10:10. So I was 40 minutes late to the stage," he wrote. "There is no excuse for that and I apologize for anyone we upset. However it was a great show and I'm proud of that."