One hacker or getting you copyrights stolen is all you need for your game to go down. I have read about on person on his blog. He created a smash hit game and a sequel with over 2,000,000 plays, and because of his Copy Rights being stolen, he could not make a third.
Another person, a friend of mine had created an online game. You can view it on YouTube, The Martial World Online. Quite a few people played that game. Because of a hacker, the game was some how partly destroyed and he had to take it down.