We have reached the point that one only needs to mention "radiation" and people go nuts with fear, no matter what the context or concentration (witness all the morons buying Iodine tables in the US after the Japanese nuclear accident).
There are folks today who are trying to do the same thing in the world of First Amendment rights, making any mention of violence, no matter in what context, the cause of a major league freakout.
Witness this story you have probably seen already, about the professor in Wisconsin who had a Mal Reynolds (Firefly) poster that had a quote from one of the show's episodes:
You don't know me, son, so let me explain this to you once: If I ever kill you, you'll be awake. You'll be facing me. And you'll be armed.
To call this a threat is absurd. In fact, in its original context, it was an anti-threat. It was a statement of old-fashioned honor by a character who lived in a violent world. And of course it is freaking fiction, and has no more relevance as a threat to real-life visitors to the professors offices than a picture of the Governator saying "I'll be back."
Not to mention the fact that such actions against speech are seldom enforced in a content-neutral sort of way. One wonders how many Che Gueverra (a real life killer) posters the university tolerates, or how many "well-behaved women seldom make history" (arguably encouraging women to break the law) bumper stickers can be found in the parking lot. The professor also had a poster taken down that explicitly advocates against violence, and had that poster taken down as well. One wonders how many similar posters with eye-catching graphics one might find around campus advocating against violence against women or violence in Darfur.