Working as a Democratic consultant in Kentucky in 2008, Emmons confronted a tracker who tried to follow Democratic Senate candidate Bruce Lunsford into a bathroom. Emmons didn't know who had hired the tracker. Lunsford lost to Senate Minority Leader Mitch McConnell.
In another case, Emmons said he had muzzle a tracker who blurted out repeated questions to disrupt a news conference by Democratic U.S. Rep. Ben Chandler of Kentucky.
Rowley has seen trackers pummel a male candidate with questions about women the trackers named, just to create questions about the candidate's relationships with them.
"There are really no boundaries these guys won't cross," said Emmons.
In Maine, LePage said the tracker went too far when he taped the governor speaking with an elderly veteran who was in poor health, though video that was eventually published showed no conversation between LePage and the elderly veteran.
"There was no need to have filmed this private discussion for political purposes," said LePage, who is well-known for his blunt off-the-cuff statements that sometimes veer into gaffes.
The 23-year-old tracker, Brian Jordan, denied the governor's claim on the Maine Democratic Party's website.
"Despite what's been said, I don't record private conversations. I don't sit outside his home waiting to videotape him or his wife going to the grocery store. I'm not lurking in the bushes or planting hidden video cameras," Jordan wrote. "I just record his public appearances."
Nevertheless, the governor demanded that Democrats call off their tracker. They've refused. So in turn, LePage is refusing to sit down with Democratic legislative leaders at a critical time, when the state's elected leaders need to introduce their plans for the next session to each other.
The back and forth points to one of the negative impacts of tracking, said political science Assistant Professor Christopher Mann at the University of Miami, who questioned whether LePage is using what happened with the tracker as a reason to stop governing.
"That seems like a rather disproportionate reaction," Mann said.
Since then, tracking has become ubiquitous, Mann said.
The practice "is really just a new media reality that we're living," said Democratic strategist Colin Rogero of Revolution Media in Washington. Those who wish it away "are standing in the way of the communications train."