At CII, there were only a couple of restrictions.
The special discussion sessions with celebrities and filmmakers are in dark auditoriums, and no flash photography is permitted. If you are caught, you must leave the presentation.
Carrie Fisher made a special request that there be no pics in her autograph session, but they were allowed in her chat with Anthony Daniels (the only presentation where flash photography was allowed, ironically).
The general rule was no pics in the autograph area, but some celebrities welcomed them, and the rule was not enforced. It was pretty much left to the discretion of the actor. The only one they enforced was pics of yourself posing with the actor - due to obvious time delays it would cause. Some of the actors with small waits allowed them though.
Barada