M.D.
It's a game for him so stop playing it, if you don't like it. He see's this as great fun. He throws something and you get it, what could be better! He is not being naughty he just needs to learn that this is not acceptable. When he throws something down or at you, then you say "ok, all done" and put it away. Do not give it back to him. It won't take him long to realize this is not a game that mommy likes and he will move on to the next thing. The key is to be consistent. If you decide to pick it up once for him and the next time it is gone, then stick with that. Only pick it up one time and the next time he throws, it goes away. Stick with what you start, if the result is the same for him every time and I mean EVERY time, he will learn quickly.