If all of the criminal element would just wear these types of jackets, the police would have a much easier time doing their job.
Old cartoons used to show the bad guy as having a long mustache that he twirled as he contemplated his dastardly deeds. Criminals were shown wearing striped prison outfits or were snaggle-toothed, wearing eye patches or masks, or leather-clad punks. These days, such caricatures of the criminal element are only used as a part of comedy. When such images are used with the utmost sincerity, as they are in Japan, it's a hoot. Frankly, I think if someone showed up who looked like the people who are illustrated in the warning signs in Japan, I think people would know enough to stay away from them.
I think the mask might be a small hint of trouble, but that's just me.
I'll miss seeing the criminal element being portrayed earnestly as ridiculous caricatures.