Call of Duty Modern Warfare 2
The opening moments of No Russian, a level from Call of Duty: Modern Warfare 2 was heavily criticised for being too violent

A study suggests teenagers who play violent video games for hours on end are less likely to know the difference between right and wrong.

 Mirjana Bajovic, an assistant professor from Brock University in Canada has claimed there is a link between the types of video games teens played, how long they played them, and the teens' morals.

She said: "Spending too much time within the virtual world of violence may prevent [gamers] from getting involved in different positive social experiences in real life, and in developing a positive sense of what is right and wrong."

Video game producers have a history of pushing the boundaries when it comes to what is acceptable and the British Board of Film Classification has previously banned three games from UK shelves.

Here are some of the most controversial games ever released, do you remember playing any of them?

Carmageddon

 

Carmageddon (1997) - Inspired by the 1975 cult film Death Race 2000, Carmageddon is a racing game where ploughing into pedestrians is rewarded with bonus points. Reputation enhanced by a shortlived UK ban.

Manhunt 2

 

Manhunt 2 (2006) - The game follows Daniel Lamb, a mentally ill man who suffers from amnesia, as he tries to uncover his identity. Daniel is, unhelpfully, guided through his journey by Leo Kasper, a sociopathic assassin. Wrongly blamed for inspiring a UK murder but banned, and later re-released, nonetheless.

The Punisher

The Punisher (2004) - The third game banned in the UK, the games features Marvel comic anti-hero The Punisher as he goes on a killing rampage after his family are murdered.

Wolfenstein

Wolfenstein (1992) - Due to its use of Nazi symbols such as the swastika and the anthem of the Nazi Party, the Horst-Wessel-Lied, as theme music, the PC version of the game was withdrawn from circulation in Germany in 1994.

Call of Duty: Modern Warfare 2

 

Call of Duty: Modern Warfare 2 (2009) - The second instalment of Modern Warfare was heavily criticised for it's "No Russian" level, where gamers mow down airport passengers with machine guns.

Mortal Kombat

Mortal Kombat (1992) - The widely popular fighting game was a must have when it was released in 1992, even if parents and American senators tried to finish it off. 

Grand Theft Auto 3

Grand Theft Auto 3 (2001) - The game that revolutionised the anything-goes mantra. Soliciting prostitutes, stealing cars, shooting up police cars: all in an hours play for gamers.

Thrill Kill

Thrill Kill (1998) - The gorefest that never (legally) saw the light of day. The game was to feature four opponents who would fight to the death in a closed room. Electronic Arts dropped it because they didn't want to "publish such a senselessly violent game".

Soldier of Fortune

Soldier of Fortune (2001) - Praised by critics, the shooter, which has Afrikana Neo-Nazis as the bad guys, was labelled an "adult motion picture" and was rated as a pornographic film. 

Postal

 

Postal (1997) - With literally no story line whatsoever, the aim with postal was to kill as many armed guards as possible. Remembered for the immortal tosh that was: "The earth is hungry. Its heart throbs and demands cleansing. The earth is also thirsty..."