Stop blindly swinging at them. Just grab onto them, get another pede to zip tie them, then take off their helmet, demask them, and grab a photo. Upload to a friendly site later or as you have time. Have a perimeter of frens because they will try to prevent you from doing this. They will get crazy because they want that anonymity more than anything. Repeat as necessary. It will be difficult but channel your emotions into smarts, not fists. Well, also fists but first things first. Have the zip ties in advance. Figure out who the phone person is in advance. Or use hidden video cameras. Do it fast. Figure out the tactics of it and share. Zip tie their feet too. If you can get a third guy to do it amid the chaos. It’ll be difficult!