I know when you experience these kind of things its gets your goat. However in the long run your probably far better off ignoring them and going on with your business. Should that not work get a patio boat (Pontoon Boat) and invite as many of your fishing buddies out as you can muster for free beer and fishing. Then have a party right there. Of course do all of this with in legal hours of the day. If its a USACE Lake I think you might have rights to go on shore... My anchor might even get stuck and a few of those brush piles might get relocated.