It's hard to get at. The "burner end" doesn't screw in, in the ones I am familiar with, the hose ends in an "aerator" (for lack of a better word) and is secured by clips to the burner pan. You could accomplish the same thing by just turning on the burners and never pressing the igniter. You'd get a better build up if you don't open the lid and let the gas accumulate inside. Which is probably what someone would do if they really wanted to hurt someone.
Although, if your purpose was to "send a message" slicing the line would be more effective.
It's a shame that they published his address, but if he installs a security camera it will cut down on curiosity seekers. When that twit was arrested in Sudbury (MA) for trying to join the "jihad" I drove down the cul-de-sac his parents lived on out of curiosity. There was a four wheel drive vehicle parked across from their driveway in a town where people don't usually park on the street. Might have been some kind of private security. I also remember the traffic jams when I lived near Amityville, NY when cars would line up to drive past the "Horror House".