A group of friends who call themselves the "Robin Hood of Keene" and put their name into action by feeding parking meters for strangers are now facing something much more serious than a parking ticket.

The group, part of the "Free Keene" movement in the small New Hampshire town, is being sued by the city itself, charged with harassing and taunting the city's parking enforcement officers, and asked to stay 50 feet away from the officers at all times.

"I was definitely surprised," Garret Ean, one of the six Keene residents named in the lawsuit, told ABCNews.com. "The city had been talking about taking some sort of action and we didn't know what they would be doing because we knew they couldn't take criminal action against us."

The lawsuit, filed by the city May 1, alleges that Ean and his co-defendants - James Cleaveland, Kate Ager, Ian Bernard Freeman, Graham Colson and Pete Eyre - have, "regularly, repeatedly and intentionally taunted, interfered with, harassed and intimated" the city's three officers by "following, surrounding, touching or nearly touching and otherwise taunting" them.

The six Keene residents have, since December 2012, committed themselves to "Robin Hood-ing," their term for ensuring that at least one person is monitoring the city streets and feeding meters with donated money so that no Keene resident has to pay the $5 fine that comes when a meter expires or the approximate $20 fine if the car is left on the street for more than two hours.

"This is one instance when you can physically prevent an enforcement mechanism of government from occurring," Ean said of the group's motivation. "The idea that you can physically shut down an enforcement arm of government, we're not at that level of success yet but it's a goal to shoot for."

Ean estimates that his group feeds $8 to $15 a day into the meters, or about $1,700 since they started in December. Keene has a population of about 24,000, according to the 201o Census.

The city's lawsuit claims the group's efforts have led to the three parking officers' being taunted online and on their days off, having had to alter their work duties because of "harassing behavior" and, in the case of one officer, experiencing "adverse physical effects."

"That kind of shocks me," Ean, who posts videos of his "Robin Hood-ing" efforts online, said of the medical claim.

"It was a positive relationship at the beginning," he said of his contact with the officer. "I tried to find common ground but within the past month or two he got more standoffish and ceased being interested in talking to us at all."

Officials with the city of Keene have not responded to a request for comment.

Ean, who makes a living landscaping and cooking in addition to the 25 hours or so per week he volunteers with the "Robin Hood of Keene," says he plans to defend himself against the city's claims using video evidence.

"Any interaction that I've done under the umbrella of 'Robin Hood of Keene' has been positive and the video evidence I've posted immediately after demonstrates that," he said. "I'd be interested to see what video they [the city of Keene] claim to have that shows any negative actions of anyone associated with Robin Hooding."