Northerly said..
I had a mate who was out recently, after arriving out the back with only one other person (a surfer) he said gday to him, and was greeted with a **** off.
This guy also at one stage grabbed his leg rope. Knowing what he was doing, my mate made sure that he fell right on the back of the surfer..
This didn't lead to fisty cuffs, but instead respect, especially after he saw that my mate could surf.
Last time someone grabbed my leg rope was over 20 years ago. I smashed him so horribly that I had to rescue swim him to shore or he would have drown. That was also the day I stopped surfing with other people... Saw where surfing was going, and what it was doing to me mentally. A few years back, I met a loner on a SUP who no one ever talks to, but goes where he wants, with impunity, and no one ever says boo. Nice enough guy when I talk to him. So I asked someone about him, and turns out some pronies started crap with him a few years back, and he smashed one of them over the head with the paddle pretty bad. Ambulance, and all that. I don't know how it turned out legally, but everyone is afraid of him now. Nice guy. Abides by the etiquette. Don't grab his leg rope

Talk crap all you want, but the second you touch someone, you better be up to it. Better to just avoid it all together, if possible.