I stream almost every sports match I want to watch. Never have any major issues doing it and to be honest half the time the streams are better quality than you get on TV. Being in Ireland where blocking these sites is pretty limited helps but it should still be perfectly possible where restrictions are tighter. I stream soccer, rugby (both codes), hurling, boxing, tennis, basketball and horse racing.
Watching Rockets Spurs now on a stream.
Also there are a few sites, one of which is superb imo, which have full game replays (particularly good for someone like me as a lot of matches are during the night, eg Celtics last night).
Anyone who wants help doing this, feel free to pm me (not sure the rules on forum for putting up links).