For a long time, European audiences were not treated to the same series that North American and Japanese audiences were enjoying. Particularly in Germany, the depiction of human violence in video games was (for a long while) prohibited in Europe. Many video games had to change either the title of the game, or the content found within, or both. For example, the popular cartoon series "Teenage Mutant Ninja Turtles" had spawned a variety of video games, but since the notion of ninjas spawn violent imagery, they had to be referred to as the "Teenage Mutant Hero Turtles" until the mid-1990s. The Contra series also fell prey to this rule. Any humans in Contra games were replaced with robots, and the name 'Contra' was replaced with the name 'Probotector'. The Probotector series lasted until the release of Probotector for the Sega Genesis (also known as 'Contra: Hard Corps' elsewhere), after which any future Contra games were released with their original titles and content intact.