Here it is, in all its poor etiquette.
There are some rules on good etiquette that most anglers know; while in many cases they aren't written down anywhere, you just know intrinsically what they are. In this case, a guy casting over your line and messing with your gear and setup is just unacceptable.
There are rules. First, don't fish the same small pool if an angler is already there. And, if you want to, at least ask him if you can work in. Don't leave garbage and bait cups behind, and always, always ask land permission for access to private property.
Unfortunately, in far too many cases, I've seen these rules ignored, and somehow we all get painted with the same brush; which can have a negative impact on all anglers.
This video was a good reminder to watch my "Ps and Qs" and not ruin another guy's outing.