I saw this on an art studio in the trendy Rixdorf quarter in Neukölln Berlin. It translates roughly as “This is no hip district!“ And a little less directly translated it means: “Fuck off, rich people and hipsters! Leave us alone and our rents low!“ I guess when you have to write a message like that it probably is aleady exactly that – a hip district taken over by rich people, hispsters and high rents.