The temperature was hovering near 90 degrees on the afternoon of Memorial Day when James O’Keefe III emerged from the woods and ambled over to my car. He was tall and thin, with pale skin and matted reddish hair. When his mug shot ran in the papers, some people told him he looked like Matthew Modine. Others said Lee Harvey Oswald. On the day I met him, he wore muddy work boots, filthy jeans and, despite the heat, a long-sleeved shirt. “Keeps the mosquitoes off,” he said. All day he was in the outback of a regional park just west of the Hudson, breaking rocks with a pickax to construct a trail. As a boy he was an Eagle Scout, but this wasn’t a nature project. O’Keefe, the man whose video stings helped take down high-ranking people at National Public Radio and led to the demise of Acorn, the nation’s biggest grass-roots community organizing group, was doing federal time.

Eighteen months ago O’Keefe and three confederates, two dressed as telephone repairmen, walked into the New Orleans office of Senator Mary Landrieu of Louisiana. This was during the debate over President Obama’s health-care plan, and angry opponents of the bill, which Landrieu supported, claimed their calls weren’t being answered. Landrieu’s staff said the voice-mail system was not working properly because of high call volume, and O’Keefe’s guys were out to get her staff to say that the phones were really fine while he captured the exchange on film. Similar strategies worked well in the past, but this time he was arrested and brought before a federal judge. In the end, he pleaded to a misdemeanor charge of entering federal property under false pretenses, paid a $1,500 fine and was sentenced to three years of probation and 100 hours of community service.

O’Keefe wasn’t happy about spending his Memorial Day turning rocks into pebbles to pay his debt to society, but what really bothered him were the terms of his probation. He couldn’t leave New Jersey, his home state, without court approval, and the court in New Orleans, where he was sentenced, had turned down a travel request. At first O’Keefe feared revealing this bit of information — “my enemies will use it against me,” he said darkly — but indignation overcame caution. “I have to get government permission to accept speaking dates, which is how I make my living. I can’t travel to work on new projects. And I can’t leave to train others.”

To him, this was the most galling restriction. O’Keefe aspires to more than making movies. He seems to be styling himself as the organizer and commander in chief of a vast guerrilla army of young conservatives trained in his methods and inspired by his example. “There are already dozens of teams out there working,” he told me. “And there are thousands more who want to learn and get involved. The more they restrict me, the more they inspire me.” He extracted a cellphone from the pocket of his work shirt. “Have you ever heard of a Russian named Solzhenitsyn?” he asked. The question reminded me that O’Keefe, who in some ways is knowing and cynical, is also just 27. For a moment I thought he was going to call the Soviet dissident, who died in 2008, but he simply wanted to access and declaim a few lines of a Solzhenitsyn speech on liberty, law and the abuse of government power, which he thought I should find relevant to his predicament.