Puzzling out “interactive” linguistic landscape data

For a paper we’re working on about interaction in the linguistic landscape, this message scrawled on an institutional nameplate on a building in Leipzig became a puzzle: What language was the message in, what did the words mean, and most importantly, what did the message imply?
We’re still working on the last question, but after some digging by our team member Richard, we found out that the words are “stop bzdurom”, in Polish (which, given the words’ location on a sign depicting a Polish Institute of Berlin in Leipzig, is intriguing), and it translates loosely to “stop the bullshit”. Anyone else working on linguistic landscape data finding bits of “interactive” data like this?