@Reymont: clearly, it consists of lighter colors superimposed over the top of a black background, reinforcing the impression that lighter shades are more powerful and should be more prominent than black things. Obviously.
This prank is clearly a white Portlander's attempt to co-opt (and thus disempower) black rage through an allusion to an already commodified version of same, NWA's "Fuck tha Police," further corrupting it by changing it to "Fuck da Police" and removing it from its racialized cultural context. Placing the statement on a digital sign further removes it from any social agency. Typical Portland racists.
I did it. Just thought it was funny. Didn't mean to offend anyone (except maybe the, you know, police). But you're right about one thing. I am totally a white dude.
....This was done by some Emo kids or the like. Its a mere coinsidence. God people always try to pull some racism out of every statue and word everywhere. Give it a rest troll.
Honestly, some of my best friends are cops.