Okay, I'm not actually a press photographer. However, I just ran into this article (via dpreview) calling for the boycott of a concert because of contracts that deny photographers much of their exclusive rights, including serious restrictions on press usage, on photographs taken of the band at the concert. What rights do press photographers have, at least in the US and UK? Is this kind of press usage protected by law?
Caveat: I'm not an attorney, blah, blah.
Your rights with respect to the image may not be as important as your agreement with the venue. If you agree with the venue as a term of attending to behave in a certain way and you don't, then they might have an issue with you. So let's assume you attended a concert and they announced that no photography or videography of any kind is permitted during the concert (a common practice).
Now, at this concert, you decide to ignore the venue's stated rules of conduct and take some photographs. Technically, because you probably don't have property or model releases, you should be able to use the image in editorial contexts. However, because you were violating the venues request with respect to allowable activities, I can see how they might have a legitimate gripe.
Short story: If you start boycotting concerts because they don't allow photography, prepare yourself to attend fewer concerts. Lesser-known acts tend to be less picky so if concert photography is the itch you want to scratch, try them.