My school runs mostly on WiFi. Kids originally weren't supposed to know the password but someone got wind of it and spread it. Now everyone uses it. Staff won't do anything about it, but they won't spread it further.
The WiFi blocks a lot of things, but it isn't as bad as most that I've read in here. Imgur is blocked with "adult", Blockland (including forums) is blocked for "games", Yahoo answers and the likes are blocked for "forums", and many words aren't even permitted to be searched, such as "proxy". Easily bypassed with "proxee" though.