So please don't take a contract out on me - I never actually left anything anyhwere! ;)
No, I just don't think there are many people that don't know leaving stuff is frowned upon. Perhaps years of seeing the wide eyed innocence of metal detectorists has left me distrustful of people doing stuff and saying they didn't know there was a problem.
BTW, I think you should have a look at Swallowhead, A few bluebells it ain't.