In my school, when you attempt to access a blocked sitea big exclamation mark comes up with the words YOU ARE ATEMPTING TO ACCESS A RESTRICTED SITE under it, and the computer makes a siren sound, like a fire engine. Then everyone in the library/computer room stares at you, and the teacher gets pissed. That's why, when searching on google and theres a chance you may find a restrcited site, turn the sound off! And once google images was blocked, and we were all sehr pissed.