Separate but related.   Some of us date back to the pre-camera phone and pad era, along with pre-Internet. In the past tourists or recorders of events, just had photo cameras, video recorders and the cine camera. Then came the Internet Youtube, social media etc.   The ball game changed and everyone and their dog is posting live music events on the Internet. Whilst photographs of public events are usually fair game, people should remember that music is copyright. Much diminished copyright, but the principle exists. You may own the recording of the event, but outside of personal use you don't own the automatic right to repost performances, or the material being performed. A large venue may rightfully have rules about recording. The music copyright point gets lost in the vastness of the largely unstoppable rise of sharing music event videos. Back to the photography, there may theoretically be image rights of the individual violated if some big time commercial use is then made of a photograph that focuses on an individual without a formal model release form.