[coldtea]

>Can you give examples of people who were arrested for no -criminal behaviour? I'd thought they were just arresting people who'd been pictures commuting crimes?

In my country? Tons. And more people who have been arrested while being non-criminal in a demonstration, and then falsely accused of criminal behavior (and with stuff planted on them).

Sometimes that gets dispelled in court, othertimes there is even third-party footage showing police planting stuff on them.

And then there are police units in disguise coming out of police vans, merging with peaceful protesters, and inciting violence and damages to break a demonstration.

>why is being arrested such a big deal?

Depends on the country. In the UK, but several others too (including mine) you can be held without trial for months (up to a year or so actually), you can get beaten up in the police department, etc.