What are the legal issues related to cameras in the courtroom?

Why might cameras be allowed, why might they be banned (protecting the identity of minors is one obvious consideration)?

Apparently today the judge allowed cameras to film the Lindsay Lohan’s appearance in court up until the time when she was remanded into the custody of the state. The cameras were ordered to be turned off when she was cuffed and taken into custody. It got me wondering why they allow filming one part but not the other? What are the legal principles at work? She’s convicted, so it’s not a matter of protecting the identity of the innocent.

I’m mostly interested in hearing from people who are aware of the legal principles, and discussing the merits of the law. Please refrain from sharing your opinion of Lohan or the paparazzi (which I’m sure many of us have).