1293's schools have St. Bernard's filters in place. No real interference with the team's operations--then again, the only sites you really need in the first place are the FIRST site, CD, and kevin.org, so maybe we're just lucky to have unblocked sites.
Having lived with it for at least two years as a student at Irmo, it's not too terrible. You just have to lay off the games and (dare I say it?) use the school computers for school work.