I agree that the people who leave trash strewn on ledges and summits are not reading the message here, and if they are they may not give a damn. They're lousy enough as people to leave their shit for others to clean up, after all.
But the point: Everyone has a duty to clean up trash they find on route and around the climbing areas they frequent, regardless of who the rotten bastard is that left the trash.
Camp 6 - weak to leave trash on a wall, but easy to grab it if you're the next party through. We took everything in the photo, leaving only a few water bottles that had been dated in Sharpie w/in the last two weeks.