Yesterday's climate march through Copenhagen was massive. I have to admit to being less than enthusiastic about protest marches in general. Most of them, I suspect, have absolutely no impact. But this one was something else.

For a start, 100,000 people turned up! The biggest climate demo in Europe ever - the two-mile-long snake of protesters brought the traffic to a standstill for a good few hours.

I was marching in the 'System Change not Climate Change' bloc, which was perhaps 20,000 strong, and we had a blast. Finally, this global movement for climate justice that we all talk about were out on the streets together. We included peasants from La Via Campesina, radical southern network Jubilee South, Friends of the Earth International, the international Climate Justice Action and Climate Justice Now! networks, and lots of Danish folk too. We had three sound systems playing everything from Public Enemy to Snap! ('I've Got The Power', of course) to Afrobeat, punctuated by powerful speeches from activists from all over the world. 

But there are always few troublemakers that spoil it for the rest of us. In this case, it was the Danish police. From what we can work out, near the start of the march, a few people threw a few stones and fireworks - pretty scary for those in the crowd. But the police's response? Charge into a completely different section of the march - our bloc, just behind where I was - and block off over 900 peaceful marchers.

They then held them our in the cold for several hours, handcuffing them, making them sit down in lines in scenes reminiscent of the US/UK treatment of Al Qaida suspects in Afghanistan. They had no access to food, water or toilet facilities, leading to many people wetting themselves and some fainting.

Then they were arrested, taken to jail cages which quickly filled up so some were handcuffed to benches in corridors, again for hours. The Danish police say it's unfortunate that some people were innocent and just in the wrong place at the wrong time. The protesters say that what they were put through amounts to torture. Details, films and testimonies here.

I had a narrow escape. But I can't quite believe what some of my brothers and sisters have been subjected to. I can only hope that the Danish people look behind the inaccurate but predictable headlines of 'riots on the streets of Copenhagen' and challenge the brutal treatment of so many innocent people, who had come to their city, and on this march, with only the best intentions.

'This is what democracy looks like', many of them chanted whilst they were penned in. Sad but true.