They are expressing ... something ... stridently.
It's just not entirely clear what.
And there's no call to action, or url, or reference to a student group... The posters are handwritten in marker, mostly all-caps, on scrap paper. (At least, the pages I read were unrelated middle pages of math or biology articles.)
Is this an April Fool's joke? If so, ... what is the joke?
[Update April 2: posters still up, so reduce the probability estimation of "this is an April fool's joke".]
[Update April 3: found a poster with slightly more context.
Updated my weight for "this is a protest or other political movement" with some connection to climate activism.]
This post's theme word is ekistics (n), "the study of human settlements, drawing on such disciplines as city planning, architecture, sociology, etc." Climate scientists of the future will focus on ekistics as a subdiscipline.