Actually pretty common on a lot of waters, with few good solutions and a lot of bad ones. Confrontation is at the bottom of the list. But there are "gorilla" tactics that make you feel better, whether they work or not.
We had one guide here who was BAD. He made the mistake of contributing a chapter to a book on AK fly fishing, in which he did a whole lot of kiss and tell on waters all over this region, but when it came to his "home" waters he actually wrote how bad it was and discouraged people from fishing there! Our solution was easy. Any time he brought clients within ear shot we'd start talking about the book (in loud voices of course!) and how bad the fishing was right there, telling each other to go read the chapter in the book for proof. Pretty quick, the last thing that guide wanted was having his clients within earshot of ANYONE!
Another guide hadn't written any chapters, but was worse than worse about trying to run the fishing scene on any waters he visited. A creative sort had a bunch of bumper stickers made up with a statement that started "I am a ....." and passed them out to all of us with instructions to stick them on the bumper of this guy's van every time he pulled a stunt. And they had really good glue!!!! The guide got absolutely frantic after a while, actually leaving his clients and following people up to the road any time he ran someone off the water. I can't imagine how many razor blades he went through, scraping those things off his rig. But he sure got reluctant to park anywhere close to other folks!!!!
It also helped that any time he got clients too close to a group of us, we'd carry on a conversation about fishing etiquette. In loud voices, of course!