
It's a pdf poster downloadable from the Kanagawa police website ... here ...
It starts by warning people who are hiring foreigners to "check their papers" carefully because ... and then it goes into a tirade about how there are so many illegal foreigners, and how many of them are criminals and involved with foreign organized crime, and how they're a threat to society, and that anyone with any info about foreigners who are staying or working illegally should report them to the nearest koban.
Nice "pictures" of the kind of foreign scum they're after too.
Lovely, eh?
I can't wait for Debito to get hold of this ...
EDIT: Um ... should I have posted this in Random Japanese Signs?