[Sleazy P Martini]

I purchased GTA3 recently and the store owner was telling me about all the young kids (7-10) who's parents were buying it for them. I'd like to hear your opinion on how old should someone be to purchase GTA3. It has a mature rating. You can pick up and "use" prostitutes in the game. That's the one aspect of the game that makes me raise an eyebrow. Since it deals with sex, should you be 18 to buy it? What do you think? I'd mainly like to hear from non minors, but all opinions are welcome.