Ok maybe a little cruel. However, unlike fish thes guys don't need room to swim, exercise or grow so a small container wil be fine and they will mulitiply as long as you have all the things they need.
I'm sure they'll be fine- keep the water very clean though, as snails can be suprisingly sensitive to ammonia & nitrites, and since they can also produce a lot of waste...What are you planning on feeding them?