Twitter use stirs up controversy at Olympics

More than 10 million Olympic-related tweets were sent out in the opening days of the London games, but as Al Jazeera's Jonah Hull reports from London, the microblogging service may be testing the organisers' control over athletes and fans alike.

A Greek triple jumper and a Swiss footballer have been kicked out of the Games for sending racist tweets and a fan was arrested for abusing a young British diver online.