Generally no. The only times we've been vindictive enough to do anything has been when they blatently acted unsafely or ignored flags etc. My view is if everyone respects each others water activities its a lot easier.
A few incidents we have acted. Diving in a shallow bay near cliffs with trainees. Absolutely flat calm sea, divers towing an SMB with just the boat covering. Fishermen on the rocks. Despite being no more than 25ft from the fishermen, bubbles visible and SMB on the surface they repeatedly cast their lines right where the divers were. After being asked by the safety boat could they please try to avoid them they continued to do it stating we didnt own the sea. Divers surface and one of them was actually struck with a hook.
Result was the 2nd wave in with fishermen doing the same both their lines were tied together and attached to the largest boulder we could find under water.
Other one is a wreck popular with divers and fishermen alike. 3 dive boats circling the area, all flying international A-flags with divers in the water. Fishing boat comes steaming towards the wreck on the plane (so high speed) right over where divers were totally ignoring the flags and very narrowly missing a pair that had just surfaced under a bag. To make matters worse the fishing boat (weekenders etc) stopped over the wreck and threw an anchor in again not checking to see where divers were or caring. This anchor very nearly hit a pair of divers on the wreck itself. The result was their anchor was cut and the anchor line tied VERY firmly into the wreck.
Most water users are fine but some seem blindingly arrogant, totally oblivious to maritime law and signals and act in an unsafe way. Its only this group of people that warrant action.