In October the Melbourne Age newspaper reported that Victoria Police had infiltrated a number of left-wing groups in the city. A police officer posing as a peace activist attended the organising committee for the Palm Sunday anti-war rally, participated in planning for a protest outside an international arms fair, and signed up as a member of Socialist Alternative.

It's outrageous that the politicians who initiated and keep approving money for murderous wars in Iraq and Afghanistan, and those who profit from selling the means to slaughter human beings, are free to walk the streets - while those of us opposed to the war find ourselves under surveillance. We should be outraged, but we shouldn't be surprised: police harassment and infiltration of socialist groups has been going on for as long as socialist groups themselves. Victoria's first socialist organisation, the Australian Socialist League, was established in 1889. Police disrupted meetings, arrested socialist newspaper sellers and hired thugs to beat them up.

Thirty years later, a couple of dozen activists set about forming Australia's first Communist Party. They were quickly infiltrated by police from the Commonwealth Investigations Branch, whose head declared that the "revolutionary incubus" was "now upon us, in our midst, threatening to engulf what remains of...civilisation".

These sherlocks believed that the party was controlled by a secret clique they called "The Secret Seven", who identified themselves with the password "kismet" and who were behind every strike and demonstration in the country. Such fantastic tales obviously helped to keep the funding flowing for spying: the CPA was a major target for surveillance and infiltration for the next half-century or more.

The political radicalisation of the 1970s led to a concerted campaign against political police in all states. In 1983 the incoming Labor government in Victoria announced they were disbanding the state's Special Branch. Almost ten thousand files that had been built up on unionists, socialists and all sorts of activists would be destroyed.

But the police are immune from democratic control when it comes to their core task. In a series of exposés in the 1990s, it emerged that not only had Special Branch continued under another name, but that many if not most of the old files had been photocopied before they were "destroyed"!

In 1997 The Age reported that undercover police had presented a breakfast program on the left-wing community station 3CR for years. Cops claimed to have sent the Rainforest Action Group broke by convincing them to spend their money in useless ways. Among more than 1,200 groups and individuals, the police had spied on the Young Christian Workers' centre in Clifton Hill, the House of the Gentle Bunyip. Police agents had also infiltrated the annual Teddy Bears' Picnic, a children's party held every year by community-based childcare centres in Melbourne.

Of course, this sort of behaviour is not some peculiarity of the Victorian police. Just last month, dozens of activists from climate change, anti-death penalty and anti-war groups found that they had been entered onto a police database in Maryland, near Washington DC, as being "suspected of involvement in terrorism".

The police everywhere exist to keep the rich rich, the powerful in power, and the rest of us in our place. Hence the importance they put on monitoring and disrupting those who might remotely pose a challenge to our rulers - from the "secret seven" all the way to the teddy bears' picnic.

Sometimes this role of the police is evident in where there resources go. Famously in 1959, as Mafia families carved up the streets of New York, the FBI's New York office had over five hundred agents assigned to fighting communism, while only five were assigned to organised crime.

But there doesn't have to be this obvious bias in resources for the police to play effectively the same role. In fact, most of the appalling things that are done to ordinary people aren't even counted as a "crime". Foreclosing on a family's home in western Sydney, getting the sack because profits come before workers' livelihoods, or being forced off your land to make way for a uranium mine - none of these things even get on the radar as "crimes" that the cops should attend to.

Rather than infiltrating corporate boards or bugging the corridors of power, the police instead treat the power structure as sacred. And they treat as criminal any sort of activity that might disrupt the "order" that makes these obscene happenings an everyday reality.

We should remember though that the most brutal or sophisticated police force can't save a ruling elite when its time has come. In the former Stalinist state of East Germany, the Stasi supposedly had more than one in seven of the population enrolled as informers. But when the regime entered a crisis and the mass of the population rose in revolt, this huge network couldn't stop the dictators, their wall and their regime from being swept into the dustbin of history.

Similarly, the keystone cops who infiltrated the early socialist and communist groups couldn't stop socialism from growing into an incredibly important part of political life here in Australia for most of the last century. And despite the activities of the latest wannabe James Bond outed by The Age, Socialist Alternative has continued to grow - and the arms fair scheduled for Adelaide this month was cancelled due to the threat of protests.

So long as we're out to change the world, people paid to lie and spy will never be far away. One of their best tricks is to involve people in some sort of pointless violent behaviour, or at least talk about it. It was less than two months ago that a number of men in Melbourne were convicted of terrorism-related offences, with the assistance of an undercover police agent who talked up terrorism and organised explosives. Our best antidote is to be open about our politics - involving mass action to change the world, not the sort of mindless conspiracy beloved of the cops.