No, it’s probably not legally binding in the least. However, Jason over at Cephalopodcast decided that when you’re a gonzo filmmaker running about, but you still need to post notice to people that you’re filming and they could be part of the crowd, why not make some yellow t-shirts that are hard to miss and put a generic release on them? Just add your particulars with a Sharpie and rock on.
Again, probably wouldn’t hold up, but as far as CYA goes it at least makes more sense than “Cape does not enable user to fly,” right?