In the following video, you first see two officers taking away a hooded demonstrator in an armlock. After they get behind a police vehicle, the armlock is loosened, the hooded man stands around casually and relaxed, and more police officers arrive to keep him and the two officers who once had him in armlock in company. The rather unusual proceedings are not disturbed by any effort to have the protester identified or at least arrested for the purpose of doing so, a rather unusual procedure considering that the protester was obviously considered so dangerous that he had to be taken away in police custody.
The video shows Berlin police officers, and we add the question of what is actually going on here:
The use of agent provocateurs is of course incompatible with what is supposed to be a democratic system, because demonstrations are a fundamental right that does not tolerate any intervention by the police. Intervention becomes necessary when demonstrations are used to commit crimes, as is regularly the case with left-wing demonstrations. But even then, intervention by police officers can only take place post hoc, after crimes have been committed, not preemptively. Intentionally causing criminal acts by undercover police officers, which in turn justify an intervention by police officers – for example in the form of arrests or breaking up the demonstration – is as such a criminal offence, e.g. a perversion of justice (§ 339 StGB), or fulfils the criminal offence of persecuting innocent people (§ 344 StGB).