From the good old days of low-res pixeling to todays high resolution blood
Sex and violence was a topic in video games since the early days of computer game history. Some people might not have realized it but there was always an urge to use forbidden topics in a virtual scenario not just since recently. Even among the first text adventures were subjects with quite a lot of (fictional) violence and blood. Remember The Lurking Horror from Infocom, a horror text adventure or Jack The Ripper which already introduced some graphical images of violence.