A perennial danger of the internet is not taking enough due care when posting something which later turns out to be complete nonsense.
But posting something as true that was rubbished months ago is pretty much inexcusable, especially when it involves religion, cannibalism and a hefty dose of scaremongering...
Back in April a story appeared in the press - heavily laced with many an 'allegedly' and 'reportedly' - suggesting the grand mufti of Saudi Arabia had issued the above fatwa.
Despite not coming from an official source many reported the fatwa as truth.
The cleric was quick to respond to the story and in a statement released via the Saudi Press Agency, said: "The fatwa attributed to us is wrong.
"It is nothing but lies ... It has been circulated to distort the image of Islam, which has elevated and granted a dignified status to men and women without exceptions..."
Despite clearing that up months ago Britain First felt the need to repost the story as true on their Facebook page on Tuesday.
As predicted the majority of comments were too bigoted to publish, but some of the tamer ones included: "Getting a bit fed up with these idiots. Let them eat each other."
"There's nothing noble about this."
Britain First regularly makes the news with its own brand of pseudo-political campaigning, most recently by getting in - and losing - a spat with comedian Jason Manford.
Other times they've made themselves look a bit silly include...