My parents actually did well enough to keep me shielded from overly violent movies and games and stuff for a pretty long time. I can hardly remember that my parents had to forbid or take away anything from me or that i watched horror movies or so in secret. (Well, i actually can remember that i was keeping a pirated copy of Manhunt [the game] secret, but i wouldn't know how they reacted if they had found out)
Might have something to do with me getting an own TV with the age of 12 or 13 and my first own PC by the Age of 14, where before both of it was only available at the shared sets at the living room, so they had a good amount of control anyways.
About that time, i think they had a good sense that i could take most things anyway (my father once bought me Syphon Filter 1 because the cashier wouldn't let me buy it) and they didn't mind what i watched, so from there on out i occasionally watched R-Rated Stuff and played violent games (wich, my father at least, mostly mocked anyway).
The only time when my parents were concerned and wanted to forbid me a violent game was, funny enough, at about Age 15, when someone gave me Resident Evil 2 (we were far into the PS2 era already) on a day where i got sick and started to get nausea and threw up while i played the game. They probably thought all the pixelated blood was too much for me ^^.
EDIT:
However, my father really didn't like if we played anything war or gunfight-like (water pistols excepted) when we were playing outside, going so far as to forcing any kid visiting us to not bring any "weapons". Our garden had a very strict no-guns policy ^^.