What's the Most Likely Chinese Version of this Odd "Chinglish"?
I gotta say this guy hit the nail on the head (bold-ed is my own):


  
  I thought it may come from Chinese that "有困难找警察" (if you meet troubles, please ask the police for help). I thought "we" in this slogan referred to the police, "they" referred to the people who is in trouble. This slogan may mean "we will protect you with all our effort" (危难时刻 我们在您身边 At the risky second, we are by your side).
  


The poster clearly says 危难时刻 我们在您身边 in Chinese above the English, and that's usually how Chinese posters (or, so called, propaganda) work.

Chinese 

English

With, obviously, some poetic license, if you will....