These conflicts are common in all societies.

I grew up surfing, and due to the sand-trapping qualities of piers, the waves tend to be a lot better there. The pier also tends to make the waves break earlier, causing a better shape to the wave.

Not surprisingly, surfers like to sit right next to the pier to catch waves. Usually this isn't dangerous because the wave most often breaks away from the pier and angles in the other direction.

Perfect, right?

Wrong, because standing along the pier is a bunch of fisherman who don't like the surfers to be so close. They yell at them, and if not obeyed, will usually resort to casting at the surfers, sometimes pegging them with the lead weight or snagging them with a hook.

SO, the surfers, in an attempt to tick off the fisherman, bring out a tiny folding pocketknife that they can tuck into their trunks or wetsuit, and cut the lines.

It's not as bad as it used to be, but most piers have the same surfer/fisherman stories.