I was riding on a SEPTA trolley the other day and a very large version of this poster was hung directly behind the driver. My first thought wasn't that this sign would deter assaults, but rather: wow, apparently there are a lot of assaults on these vehicles. And that led me to wonder whether this sign functioned more like a broken window, hinting to potential miscreants that transgression is now the norm. (And simultaneously making an insufficiently credible claim that transgression will not be tolerated.)
"I will prosecute to the fullest extent the law allows"? Does that really make the criminals quake?