I've found the pond snails having orgies in my filters!!! (I was wondering about the faint sounds of house music & clinking glasses @ 2:00 AM!)
I don't sweat it. I remove what I can, when I can. I find the babies really tough to handle, and I can only get at the egg sacs on the glass. I have a good friend that is a director of the Boston Macological Club (a shell club but they study mollusks, I know, nerd alert). I asked him what to do, and he said to return them to a local pond where they will be food for larger fish (circle of life & so on) BUT I really don't have the time to visit a pond all the time. I'm thinking of just getting a jar w/ a salt solution to drop them in, hoping for a quick death.