A tweet by conservative columnist Erik Rush — that all Muslims should be killed in response to the Boston Marathon bombings — has set off a firestorm of debate on Twitter.
The hashtag #muslims was trending as pro- and anti-Islamic voices weighed in.
In what was widely described as a "joke," Rush tweeted:
When a responder tweeted, "Are you ALREADY BLAMING MUSLIMS??" Rush responded:
"Yes, they're evil. Let's kill them all."
He later tweeted that he was being sarcastic.
However, when a predictable flood of abuse, shocked disgust and the occasional encouragement came, Rush appeared defiant, retweeting the more profane of the responses.
Some reports referred to Rush as a Fox News contributor. Carly Shanahan of Fox News told GlobalPost on Tuesday: "Rush is not a Fox News contributor, he is only a guest and not even a regular guest of the network - he has been on a total of five times in the last twelve months."
Here is a cross section that we found representative of the reaction.