On the corner of Liberty Plaza at 4am, members of the Occupy Wall Street protest watched, helpless, from behind a row of New York police officers, as their tents and belongings were shovelled into a rubbish van. They were surprised in the small hours of the morning, dragged out of their tents and arrested if they refused to leave the square which had been their home for months.

Blocked off by police, some of those protesters were now huddled in the doorway of an HSBC with the blankets they had managed to snatch, calling their friends, trying to locate those who had been arrested. Behind the barricades, you could see police feeding the entire intricate, beautiful mess of Occupy Wall Street into the teeth of an enormous waste compactor.

A few hours ago I was in the bustling heart of the Occupy Camp, deep in conversation over coffee and bread pudding with a group of animated young people. By 4am, a pile of rubbish was all that remained of the media tent, the drum circle, and the library with its 5,000 books. The two-month-old camp at Liberty Plaza, the heart of the global Occupy movement, has faced down eviction attempts before. This time, however, police struck without warning and in the middle of the night. A few hundred activists were curled up in their tents when riot police and sanitation workers stormed in and ordered them to leave immediately, with or without their belongings. In the sterile zone behind the police line, protesters were marched out of the square in ones and twos.

All of the bright, hand-painted signs and placards detailing their political discontents and visions for a fairer future were dumped in the rubbish piles. The only thing that was left, as all traces of dissent were scrubbed from the square, was a large American flag flapping in the early morning breeze. The NYPD can be persuaded to do a lot of things in the name of freedom, but they have their superstitions.

Accredited members of the press were refused access to the square and penned where it was impossible to see what was happening. Some were arrested; others had their press passes seized. I narrowly escaped arrest as I was escorted out of the secure zone for having the temerity to update my Twitter feed. At the intersection of Broadway and Pine Street, hundreds of angry protesters linked arms and chanted to stop one of the dump trucks leaving with their belongings. Then the NYPD moved in with batons to clear them away. By the time dawn broke over Manhattan, protesters were holding an impromptu general assembly in nearby Foley Square. Most had not slept and, as some dozed by the empty fountains, some resourceful soul organised breakfast for the shell-shocked.

As I write, that meeting is still ongoing – but whatever Occupy does next, Mayor Bloomberg's decision to evict the New York camp can only galvanise support for a movement whose momentum had begun to deflate.