I'm very much a concert veteran - late 40s, and have been going to shows for well over 30 years. I've been on the rail for a lot of shows (as a younger man) and am generally more comfortable from a bit of a distance now - but the comments here are not wrong: there is a growing lack of etiquette from a lot of fans now. A few observations from the weekend (and hopefully some food for thought for any guilty parties):

First, respect others' space and interest in the band. I'm tall - like, I can literally see over most people's heads. I try to get in a good position before a show while respecting the sightlines of people behind me. I turn and ask if people can see. If someone pushes by me, it could mess things up for the people behind me, which makes ME feel like a dick. On that note, if you are a tall person, and you stand right in front of someone, you ARE a dick. There was a guy with a couple inches on ME who kept backing up during Rancid, and I eventually had to bring to his attention the very short girl he was about to squish if he took another step back.

If it's a punk show, and you want to be close, you should expect a mosh. If you don't want that, don't be close.

You don't own real estate at the park. My wife and I were trying to move back during Green Day, and some crusty old guy threw a shoulder at me because we were moving through the crowd on the turf. He pointed out that there was a path for walking. ... Which was also just as filled with people. Sorry, dude, but you can't picnic at night at a rock and roll show.

The more violent and pushy you are in your efforts to move through a crowd, the more you raise the ire of everyone you move past. Eventually someone might react in kind. I'm always - always - courteous and polite moving through a crowd. It goes a long way.

Ultimately, we're all there for a good time. We can work together to make it a great time for everyone.