If the restaurant didn't block Graal's ports, and someone really was IP banned, isn't the real problem that kid who thought it would be funny? It is not the end of the world if you can't log onto Graal at a certain restaurant. The ban solves more problems than it creates. For example, if your brother got IP banned and you can't log on at home, have a chat at the dinner table with your brother. Talk to him about why he shouldn't have gotten the IP banned. What would you rather do, let people take advantage of staff and hack new accounts, ruin Graal for other people and make the staff team look like idiots? Or get caught up in a small problem that is fixable?
If you don't like the game, don't play it. If you like the game, but think you can do better yourself, get Playerworlds and make a server by yourself. See how that turns out, and compare.