Ever had one of those races where you wish you could just cut a corner and get the whole thing over and done with? Well, ever thought about making this a habit? It seems one Kip Litton in the US has for quite a lot of his races and it's got the attention of the running community over there.

Exploring the Web sites for each of Litton’s marathons occupied Strode for several days. Not every race was as well documented as Missoula’s, but wherever professional race photographers had been present he hunted for shots of Litton among other runners. He found images of him at the end of a course, only twice at the beginning, and never in between. And there was the chip-gun differential: with rare exceptions, Litton started two to five minutes behind the leaders. In a crowded field, wouldn’t a swift runner want to avoid weaving through clusters of slower runners?
— Is Kip Litton a Marathon Fraud? : The New Yorker

Despite a lot of evidence of cheating and disqualifications, it seems he still denies cheating and of course it means no one knows exactly how he did it, though the bicycle behind a tree theory seems the most plausible.