This photo is making the rounds on Facebook (over 19,000 likes and 11,000 shares). I don’t know the original source or where this photo was taken, but the form of the message is something with which every German speaker is familiar. So an explanation may be necessary for everyone else.
At the end of every ad for any kind of drug, the (presumably mandatory) unvarying announcement can be heard, “For the risks and side effects, read the package insert or ask your doctor or pharmacist.” It’s usually spoken very quickly, like the details at the end of an American car commercial.
This banner says “For the risks and side effects of Nazi marches, read a history book or ask your grandparents.”
Television advert image found here