Athletes at the London Olympics will be allowed to blog and post on Twitter but could be thrown out if their musings breach guidelines.Competitors may write only “first-person, diary-type” entries but should not act as reporters, International Olympic Committee (IOC) guidelines say.All social media activity must respect the Olympic Charter, which bans political demonstrations.
http://news.bbc.co.uk/sport2/hi/olympics/london_2012/13927076.stm