The International Olympic Committee is barring competitors, as well as coaches, support personnel and other officials, from writing firsthand accounts for news and other websites.
An exception is if an athlete has a personal website that was not set up specifically for the Games. [ed. see, for example, bobbyjulich.com]
The IOC’s rationale for the restrictions is that athletes and their coaches should not serve as journalists — and that the interests of broadcast rightsholders and accredited media come first.
[…] To protect lucrative broadcast contracts, athletes and other participants are also prohibited from posting any video, audio or still photos they take themselves, even after the Games, unless they get permission ahead of time. (Photos taken by accredited journalists are allowed on the personal sites.)