Runners that cheat

I first heard about people that actually cheat in marathons and other similar distance races in Runners World a few months back. What a bizarre concept! Why in the world would someone cheat in a race? I guess I see WHY pro athletes cheat when it comes to bettering themselves to keep their jobs, I don't think it is necessarily right of course, but isn't running races about self improvement and health? What satisfaction do you get by finishing a race by cutting through the course, or signing up for a marathon but actually running the half?

 Another way people cheat is to buy the bib of a runner that qualifies for Boston, or have someone faster then you wear your bib in a Boston qualifier. I just don't understand the psychology behind this.

Cheating is so common that they have actual committees that watch for it, studying previous times in races, whether times registered from their bibs when they crossed mats (if they didn't this is a good sign they cut through the course somewhere) sometimes they even need to look through race pics to look for cheaters. The first time I read about cheaters was a story about a man that the race committee noticed in a finish line pic. He wasn't in the best physical shape but he crossed the finish line looking pretty darn good, in a cotton t shirt with nary a sweat stain! Just that picture alone piqued the interest of the race committee and sure enough, they did some digging and found that not only was he a repeat offender in the cheating department but he also wrote checks that bounced for multiple races. I would love to know his reasoning behind this. Was it a good story to post on his Match.com profile?
 Here's a blog that is dedicated strictly to catching and researching these cheaters. I appreciate people that dedicate time for outing these people, hopefully it deters others that might consider doing this. Training for a race takes literal blood, sweat and tears and to see others take places in races that one must qualify for, or lie about their age to earn records, use others bibs to run races they didn't qualify for, it really and truly is a disgrace and these people should be ashamed of themselves.