How to get arrested before you've done anything wrong

It's discomfiting when you talk to a Danish activist about policing techniques and she describes the "English method" as "picking up a few specific people and pre-arresting protesters". It's even more unnerving that she's right. No fewer than 11 people were arrested in the run-up to the Camp for Climate Action's attempt to close Ratcliffe-on-Soar Power Station on 17 October, on suspicion of various conspiracies.

Of the 114 activists who were arrested in April while allegedly planning another action, 25 were charged with conspiracy to commit aggravated trespass (described to me by one lawyer as "using a mallet to hit a drawing pin"). Officials waving the Terrorism Act, meanwhile, stopped four activists who were heading to Denmark for some early organisational work.

The British police are getting into this pre-arrest idea. Will they be doing the neighbourly thing and popping over to Denmark before the climate change conference in December with some handy info, pictures of their favourite activists and tips about pre-arrest? I expect so. Don't you?

It will be interesting to see what methods the Danish police use to tackle the thousands of activists who will be pouring into Copenhagen. Any reassurance gained from a very cuddly report about the new Copenhagen bike-cop unit is soon dispersed by a video I'm told to watch on YouTube of a confrontation that took place at Brorsons Kirke in Denmark last August. Some Iraqi asylum-seekers had sought sanctuary inside the church in an attempt to avoid deportation. They had been holed up there for two months when the police announced their intention of coming to get them out. Within hours, a coalition of about 300 activists and local people came out into the streets, determined to stop the police by peaceful means.

The video is filmed after dark, and is, at times, unclear. But unmistakably it shows a police force completely out of control, using its truncheons freely, grabbing protesters' hands in order to hit them, shouting inches away from people's faces, and directly pepper-spraying seated activists who are offering no resistance whatsoever. At one point, a woman is beaten from behind so savagely that she tries to move away but just collapses to the ground. That scene in particular keeps replaying in my mind.

The police eventually managed to get into the church, took the Iraqis away and, the following day, forcibly repatriated seven of them. There was a huge outcry. The Danish Church was reeling and thousands of people marched in support of the asylum-seekers. Forcible deportation continues to be a deeply divisive issue. At a more recent demo, the police were far more low-key. But will that last, when the barricades go up?

Talking of which, the latest news is that the police have ordered a water cannon for December. According to a police spokesman, however, it is not just for dispersing protesters and barricades: "It can also be used to put out blockades that have been set on fire." And watering the flowers, no doubt. Suddenly, "English methods" don't look so bad.

This article first appeared in the 26 October 2009 issue of the New Statesman, New York / London