most families have their black sheep. In a Muslim family, that black-sheepery might well, in current circumstances, take form of going off to join IS, mightn't it?

It might. Then again they might be accepted for doing it. We have been here before: a hell of a lot more British Jews have gone to fight for the Zionists in Palestine (in some cases, killing British and American military for the cause) than there have been Muslims goijng abroad to fight.

http://en.wikipedia.org/wiki/Mahal_%28Israel%29

Did these sick fuckers get treated by British Jewry on their return as the psycho bigoted killers they were? Maybe sometimes, but it certainly wasn't their usual reception.

There are currently about 100 British people in various Zionist armed gangs in Palestine, and about 500 British people fighting for IS:

http://blogs.channel4.com/factcheck/factcheck-britons-fight-israel/18448

There are about 10 times as many Muslims as Jews in the UK, so that means, proportionately, twice as many British Jews as Muslims go abroad to kill. Currently British Muslim psychos are a numerically larger problem, but over the decades since WW2, they have been vastly outnumbered by British Jewish psychos and are only just starting to catch up.