Cutting off other people's leaders would only escalate the bad tension that is brewing up nicely among the Vedder crowds these days.
It's not a solution, but only makes you part of the problem. Not to mention the disposed fishing line that has been snipped off on the river banks. Again, treat others like you want to be treated. Inform the ignorant and oblivious individuals who get in your way, instead of wasting your precious free time by stirring things up.
Honestly, I've never had a problem on the Vedder. The biggest crowd I've fished with is maybe 10 people, and that's distributed across a 50 to 60 meters stretch of river. If you choose to fish the popular spots, be prepared to put up with all kinds of people. A walk to a distant spot will usually result in peace and relaxation. The people who show up at those spots usually have the same objectives as you. Again, you are one of the thousands who fish the Vedder each week, please do your part to make this fantastic fishery better.
Regarding language barrier/communication problems, I think all of us agree there is a growth of different ethnic fishing groups in the last several years. Several years ago while meeting with one of the fisheries manager I brought up the importance of regulation guides in different languages. It only makes sense as we do receive a tremendous amount of overseas tourists who come here to fish. Maybe something not as detailed, but a permanent copy of the generic regulations that need to be followed at all times is needed for the major languages.