The thing about jokes (and I realise this is a very complex issue for a lot of people to have to face) is that they need to be funny to qualify for the title. Death threats are generally not amusing. Death threats against women made specifically in a way that shows your contempt for their gender and their religion are particularly unfunny.
http://www.bbc.co.uk/news/uk-england-birmingham-11736154 "A Conservative Birmingham City councillor has been arrested over allegations he called on Twitter for a female writer to be stoned to death."
Still, at least it looks like there are consequences.