When rap music first emerged in the 1970s, a lot of artists didn't really mention crime. Gangster Rap would tackle some similar themes, but it would do it in a much more provocative way. The authorities had to find a different way to stigmatize rap if they couldn't ban it from the charts. So Snoop Dogg actually was an early artist who had his lyrics used against him and he had a song called Murder Was The Case. In American Britain, you now have police units which look on social media for rap music videos or lyrics that mention violence or crime.