There's an old saying that circulates in more politically radical circles: "Protest is patriotism." In this post-September 11 world of paranoia and political expediency, however, protest, an essence of democracy, has morphed into something perfectly Orwellian: terrorism.

Two recent events demonstrate how easy it is for the government to dilute words and their meanings to close off opposition and dissent. Last week, the Maryland state police disclosed that 53 nonviolent anti-war and anti-death penalty activists were tracked for 14 months in 2005 and 2006 under the state's terrorism surveillance programme, and that their names had been added to the state's and the National Security Agency's database.

Who are these sinister terrorists? Two of the activists caught in the Maryland dragnet are Carol Gilbert and Ardeth Platte, Dominican nuns in the Roman Catholic Church who did indeed break the law in acts of civil disobedience. On October 2, 2002, in response to the first anniversary of the war in Afghanistan, they broke into a missile silo in northeastern Colorado and painted bloody crosses on it.

Understanding that acts of civil disobedience carry grave consequences, Gilbert and Platte paid a hefty price for their protest: they went to prison. Gilbert received 30 months in a federal penitentiary while Platte was sentenced to 41 months for injuring government property and obstructing national defence. The nuns no doubt agree with Thoreau's famous saying: "Under a government which imprisons unjustly, the true place for a just man is also a prison."

But being labelled terrorists is too much for them. They say they protest in pursuit of peace and truth. "We're Dominicans. Our mission is 'veritas', which is truth," Gilbert told the Washington Times. They aren't even sure how their names were included in the Maryland state police's database, since they say they weren't involved with the protests the state police say they monitored. The surveillance programme has been shut down, and police superintendent Terrence Sheridan admitted to the Maryland Senate last week that "The names don't belong in there. It's as simple as that." The activists have been notified that they can review their files before they are purged from the databases.

Farther to the north, another state is experimenting with a far more audacious assault on democracy. In 2002, Minnesota liberalised the legal definition of terrorism, according to the Associated Press, to include actions "intended to interfere with the conduct of government or the right of lawful assembly." Essentially, it's Minnesota's version of the US Patriot Act.

Ramsey county police used the statute to break up an anarchist group called the RNC Welcoming Committee that planned to carry out direct action protests, including roadblocks, to prevent delegates to the Republican national convention from entering the Xcel Center in Minneapolis. Eight leaders of the organisation were arrested before a protest was even launched. They face seven and a half years in prison if convicted.

No doubt these actions are crimes, but as Stephen Vladeck, associate professor at American University Washington College of Law, told the AP: "One of the biggest concerns among scholars who debate the definition of terrorism is that an overbroad definition would both dilute the real sense of terrorism and punish conduct that has traditionally been a far more minor offence."

What's frightening about these recent incidents is twofold. First, the Maryland police programme raises the question of how extensive this devolution of surveillance from the federal government to individual states has become. We already have the national security state. Must Americans worry that state and municipal governments will also increasingly monitor peaceful people who participate in political activities?

Second, the terrorism charges brought against activists like Gilbert and Platte and the members of the RNC Welcoming Committee have, in effect, criminalised protest. This is all the more serious because Minnesota had the audacity to not only revise the terrorism statutes to hamper acts of civil disobedience but also to bring such draconian charges against the group's members before they even committed a criminal act. Seven and a half years for planning to block entrance to the Xcel Center, spray police and delegates with urine and even spread marbles on the ground a la Animal House is excessive and ridiculous.

Again, there's no doubt that these actions would get the protesters arrested, possibly even charged in earlier times with a felony, but to suggest this is terrorism says much about our society. Those in charge will not tolerate a vibrant culture of dissent - a novel irony in such an overwhelmingly Christian country whose saviour found himself on a cross for his civil disobedience in the temple.

The group's activists have no illusions about what Ramsey county is up to. "Conspiracy charges serve a very particular purpose - to criminalise dissent," the RNC Eight wrote to their supporters. "They create a convenient method for incapacitating activists, with the potential for diverting limited resources toward protracted legal battles and terrorising entire communities into silence and inaction."

It's startling to think that in the US we even have the pretension to argue about the merits of exporting democracy when such blatant authoritarianism continues to run rampant here at home.