I was out in a farmer's field this morning where I have permission. A lot of others have permission too and I suspect quite a few others who don't have permission hunt there as well.
The farmer is kind enough to grant permission to just about anyone who asks so I think it is very disrespectful to litter his field. He even left a small stand of corn up to make a good hiding place and in among the constalks I found dozens of spent shells. I only had a small vegetable/fruit bag from the store with me and easily filled it up and could have easily filled another one.
I have found dozens if not hundreds of shells in popular places at Boundary Bay too.
I don't want to sound like a bitchy school marm, but Jeez guys, pick up after yourselves.