How do you miss stuff like this? Seriously, with the world the way it is today, letting this stuff slip is not smart at all.
The offending multi-storey street art (seemingly heavily inspired by the cover of 1981 Black Flag single "Police Story", as noted by PC Gamer) depicts a policeman wearing a badge emblazoned with the number "FA6607" - an obvious homophobic slur, albeit presented in leetspeak.