"Terrorists Use Comedy to Recruit" joke

Researchers in Singapore say terrorists have begun to post comedy and Top 10 lists on the internet to draw in young recruits.
Samples include:

- “Knock-knock.”
“Who’s there?”
“Praise.”
“Praise who?”
“Allah.”
- A priest and a rabbi walk into a bar, and we blow them up.

- If you have breasts and I can see your face, you might be an American woman.

- How many Israelis does it take to screw in a lightbulb? Zero – there’s no such thing as an Israeli.

- Why did the American cross the road? To get away from the twin towers.