I meant to post this earlier (it's a couple of weeks old), but now turns out to be a good time.
Why would you call the police even if the sign had been in Arabic? (It's Hebrew.) How stupid can people get? How timid? How cowardly?
Here's another incident, from Texas (naturally):
This bright 14-year-old kid made an electronic clock. But because he's brown - and Muslim - he was arrested and taken in handcuffs to juvenile detention.
Here's the article in the Dallas Morning News.
Police say they may yet charge him with making a hoax bomb — though they acknowledge he told everyone who would listen that it’s a clock.