It all started as a flame war which got out of hand and ended with real flames burning down a man's house. Here's a story about an Internet feud turning really bad:
Barbs were traded, insults thrown and threats made in an environment that grew increasingly hostile. The social networking site had morphed into an anti-social one. And for Tavares, it came to a head when John Anderson, a Yafro member calling himself Johnny Darkness, posted a digitally embellished image of Tavares.
The photo composition showed Tavares cradling a laptop in one arm, a pistol in the other and wearing a shirt with a pocket full of pens. [...]
Tavares flipped. Anderson taunted him, daring Tavares to make good on his threat to "come and kick my butt", never believing for a moment that someone who lived 2000 kilometres away could physically threaten him.
But on October 9, 2005 - after driving from his base in Virginia, near Washington, DC - Tavares pulled up near a compound in the small community of Elm Mott near Waco in Texas.
There he knocked a hole in the side of a mobile home between a propane gas container and the hot water system, poured in a mixture of petrol and Styrofoam and ignited the flammable cocktail with a flare. Moments later, the home belonging to John Anderson was engulfed in flames.
Link - via Cowboy Caleb