I always thought there was a ceremony for burning a tattered/torn/dirty flag. It's usually done with respect. Those guys look like they are VFW or American Legion. So I would say they are burning old tattered flags. Nothing wrong with that.
As far as freedom of speech. The one thing I know is as long as the speech doesn't interfere or disrupt another persons pursuit of life liberty and the pursuit of happiness, then it's protected. Once it started interfering with those, then there's a problem. Things like slander are not protected. You can get in a lot of trouble for calling someone a lier or cheater, but you can pretty much get away with calling them mutherf*cker and other colorful terms. Just watch Penn & Teller's show "Bullshit". If someone wants to protest by burning a flag, then fine. As long as they don't have a problem with me tossing buckets of water on it when they light it.
That my