Kaczynski is the name of both Polish president and prime minister. Kaczka in Polish means duck, so many people call them colloquially "ducks".
One guy posted somewhere in the web sentence: "I will buy a gun and shoot the ducks". Few days later he got arrested by the police. Luckily, they believed him that it was just a joke and after two weeks of investigation he was not presented with "attempt to kill Polish president and Prime minister" charges, but he will "only" be charged with "causing unnecessary mobilization of public forces and starting false alarm".
That feels really insane. I do agree that a joke was stupid and inappropriate, but still, to put the poor guy in front of the judge for that?
link in Polish