The way I've seen it done was if this is part of a HS or some other K-12 system, the school will have a media release form the students have their parents sign at the beginning of the year stating that throughout the year the student may be subject to having their picture taken by various approved sources such as newspapers, the school year book, etc. And if a students picture appeared in a public resource, without that paper signed the parent was on legal grounds to sue if they so wished.
I've also seen when I was in HS Band doing football games flyers posted all over the place in plain site (the gates, concessions, at the front of the bleachers, etc) signs that said "During tonights game press will be here to take photos and will do a live broadcast during the event. By being here, you are agreeing to allow yourself to be photographed, filmed, or in the background of either format. If you do not wish to be apart of the filming or picture taking process, there are specific marked area where the camera crews are not allowed to shoot towards or around, they have been informed of such areas and you can expect your rights to be respected."
Paraphrased slightly but our local news agencies record highschool football games on friday nights for a specific segment on the late night news.
Could implement either of those policies.