Kara Bonneau had trained for months to run the 2014 Boston Marathon, one of the sport’s premier events. Excited about the challenge ahead of her, she posted a photo of her official race bib #14285 on her various social media accounts so that her friends and family could track her as she traversed the 26.2-mile course.

Mary Pilon is the author of The Monopolists and the forthcoming The Kevin Show. She primarily writes about sports, business, and politics. Sign up to get Backchannel's weekly newsletter, and follow us on Facebook, Twitter, and Instagram.

After crossing the finish line, Bonneau punched her bib number into the Boston Athletic Association’s website to look at the snapshots race photographers routinely take at various checkpoints of the race—both to sell as souvenirs and to verify results. She was surprised by what she saw. The photographs showed four different runners. None looked like her, but all sported bib #14285 as they trotted along the trails. Confused and outraged, Bonneau posted the images to her blog, asking for readers to help her solve the mystery of the other runners’ identities. The seeds of #BibGate2014 were sown.

Bonneau didn’t yet know that she was part of a scam that has become a trend in the racing world: social media banditing—where a runner uses social media to enter a race without officially registering. This typically means lifting a bib number off of someone’s Instagram ahead of a race, creating a duplicate, and then using the hoisted entry to run a race incognito. It’s a phenomenon born out of the current dual booms of technology and endurance events—and the very tools bib counterfeiters are using to circumvent race regulations are also being used to bust, ban, or—in some cases—publicly shame cheaters. And many are still divided about whether it’s a silly prank or a serious threat.

“I was just really shocked,” Bonneau tells me. “I think I would have been upset to see cheating in any arena, but because the Boston Marathon—and particularly this Boston Marathon, the year after the bombing—had such special meaning to me, I was really angry.”

For professional athletes, the motives for cheating generally are more obvious: money, fame, and often a low likelihood of being caught. But why would a middle- or back-of-the-pack runner lie or cheat in a race that doesn’t even matter?

Long before social media made things like bib replication easier, banditing at major races was viewed as a brave act. Rebellious runners like John Tarrant gatecrashed races as a political statement, in protest of rules about amateurism that limited how much money athletes could earn in appearance fees and endorsements. It was an underdog move against the proverbial Man. Darren Garnick, a filmmaker and runner in New Hampshire who bandited the Boston Marathon in 1986, said he laments this shift from those days to today’s anti-bandit culture.

“I think it’s sad there’s this crackdown,” Garnick says. “I remember after finishing the marathon then that I was beaming. You can’t take your car on the Indy 500 track and you can’t just walk on a PGA course. But the Boston Marathon is world-famous, and you could be a part of it. I don’t remember marathon bandits being considered a threat or a freeloader or a cockroach then.”

Organizers with New York Road Runners estimate that of the more than 50,000 runners who hit the starting line each year, the number of marathon bandits typically never exceeds 50. But the threat of banditing was large enough for the NYRR to create an anti-banditing campaign: “Respect the Run.” The campaign launched this spring, featuring amoeba-like cartoons stealing bibs and proclaiming it “risky business.”