Members of the Olympic Resistance Network said police are using intimidation tactics to silence their protest against the Vancouver 2010 Games. (Canadian Press)

Protesters opposed to the 2010 Winter Games in Vancouver said police are using intimidation tactics to keep them quiet, and they are threatening to take the police to court to put a stop to it.

A group called the Olympic Resistance Network sent a lawyer's letter to the RCMP unit in charge of Olympic security demanding it end what the group calls its abusive and unlawful conduct against its members.

The group gathered at the Olympic countdown clock in downtown Vancouver Wednesday to call attention to what it says constitutes harassment.

The protesters claimed that even though the group does not condone violent protest, police are following them and questioning their neighbours and family to learn more about their plans for the Olympic period.

Cara Fisher admitted she is opposed to the Games but said that doesn't give police the right to knock on her neighbours' doors or show up at local businesses asking about her whereabouts.

"The RCMP visited a diner in my neighbourhood inquiring if I worked there and saying they needed to speak with me because I was a witness to an accident,” Fisher said.

Fisher said she is one of approximately a dozen protesters who have been under surveillance over the last few weeks.

She said she never witnessed any accident but believes police are trying to find out if she plans to disrupt the Games, which begin in February 2010.

St. Sgt. Michel Cote of the Vancouver Integrated Security Unit told CBC News the police have not approached the group about backing down from their Olympic protest.

Cpl. Bert Paquette said the unit does try to respect protesters' rights to privacy.

"What we seek to do is either confirm or disregard individuals as potential threats to the safety and security of Canadians and visitors to Canada who will be here during the Games," Paquette said.

Such police tactics violate the protesters' constitutional rights, said David Eby, executive director of the B.C. Civil Liberties Association.

"We respect and appreciate that we've asked the RCMP to do a job, which is to keep the Olympics safe, and they have a role to play in doing that, but we're very concerned that the tactics we're seeing will result in a chill on free speech,” Eby said.

Investigators argue they are not breaking the law by gathering information about potential threats. They said they will review the group's letter and draft a response in the coming weeks.

Another member of the network, Garth Mullins, said they don't intend to stop protesting.

"Blockading roads? What does that mean? We have protests in the street all the time in Vancouver," said Mullins. "It's part of a civil society, and we expect that to continue."

He said the police are trying to send a message.

"It sends a chilly climate: the police are watching you. We know who you are. We know where you live," Mullins said.