re: NL politics, but in English
@j0 It's a way to break up the protest; they can legally arrest someone on a flimsy "suspicion", hold them overnight, then never actually charge them and release them the next day (or even the same evening) - but by that time the protest will have been completely killed off by the arrests.
They usually primarily focus on the most energetic protesters, who 'drive the vibe' so to say. For bonus points, they also get the fingerprints of everybody they've arrested, despite there being no charges.
re: NL politics, but in English
@j0 (Of course it is also very useful for just generally intimidating protesters, to discourage them from joining the next one)