Through the gift of anonymity...
Let's face it, I would kick your ass if you said that to me in real life.
EDIT: To participate more, I was once assaulted on Gears of War 2 online. Some punk from Yankland, after talking about his plans to go and have a McDonalds, in painful detail, I was abused for having used my chainsaw once. Unfortunately, according to his wacky teenage logic, that's all I'd been doing. He messaged me:
"Yo dude, you're so bad all you can do is chainsaw..."
I replied thanking him for delaying his trip to McDonalds in order to insult me, then informed him that his argument was flawed.
"Wow ur gay" Was what I got in return.
"Scathing in it's elegant simplicity, 'ur gay'", said I, in return to the wondefully crafted witticism. I recieved no further communication from him, so I assumed I had won that battle of wits.
EDIT 2: Just try and act as civilised as possible and use logic, that defeats the troll.