The police justification? "There is a risk that a speaker will repeatedly be shown via video who in the past made antisemitic remarks and glorified violence. For this reason, the gathering was ended and banned on Saturday and Sunday as well." - nothing that actually happened, but rather for a suspicion that words might be said later, the entire conference was immediately terminated, banned, and violently evicted. There is not much video of the eviction since filming private gatherings is generally illegal in Germany. https://mondoweiss.net/2024/04/police-raid-berlin-conference...
No sane resident of Germany would risk it. You comply with the government or else, no different than Russia or China.