"The ISIS needs YOU, citizen!"
They'd be more convincing and persuasive with a few classic propaganda posters and slogans.
Heh this made me laugh making me think of those old Civil War era Uncle Sam posters lol.
From the atheist/secularist mindset their propaganda and tactics do certainly have to seem like failures, if not out right laughable. I myself used to think scary enough a lot like you do.
Here's the problem though; Aunty ISIS isn't trying to recruit you, lol, you're the kafir to them and are their enemy. The brutal Reality is that ISIS is in fact one of the most formidable, effective, and brutal military fighting forces on the earth today. While you and I are clearly not deceived by them, it is an inconvenient truth that their propaganda techniques and tactics are sadly very effective.