memes

I don't know too much about it tbh, but as far as I know the laws are about racism and antisemitism in general. It is then up to the police to interpret what is antisemitic and what isn't in order to prosecute. And then also up to the judges discretion if it goes to trial. So for example there is no law that explicitly forbids "From the river to the sea" (as far as I(!) know) but if it could get "reasonably" interpreted as antisemitic you're fair game.

So you're at a rally and starting a chant or have a particular slogan as part of your speech, the whole rally could get disbanded and then they figure out the "exact legalities" later. The police are allowed to do mistakes in the name of combating antisemitism, you're not.

Again this is from kind of hearing and reading about it, not too knowledgeable about it.

https://theleftberlin.com/how-germany-tries-to-ban-the-slogan-from-the-river-to-the-sea/

Diese Mehrdeutigkeit sieht die Richterin nicht. Die Parole [from the river to the sea] könne nur bedeuten, das Existenzrecht Israels zu leugnen, da gefordert werde, einen palästinensischen Staat zu gründen, »für den Israel wegmuss«. Es sei »ganz klar«, dass damit das Massaker der Hamas gebilligt werde und damit Mord, Vergewaltigungen und dass Kinder massakriert wurden. Relevant sei nicht, was die Angeklagte für sich damit meine, sondern was bei unbeteiligten Dritten ankomme. Das Motto der Demo hält die Richterin für vorgeschoben, es sei offensichtlich nur um Palästina gegangen. Deswegen verurteilt sie die Angeklagte.

https://www.nd-aktuell.de/artikel/1184315.from-the-river-to-the-sea-berliner-gericht-verhaengt-geldstrafe-fuer-umstrittenen-losung.html

I mean he is kinda talking about that. The guy he mentions is a journalist that was sanctioned (no judge needed) for "wrong speak".