Since I wrote this, the people originally listed as placing first and third in the men's 60-64 age group at the Soldier Field 10-miler have been disqualified. In both cases, detective work by Andrew Suozzo and I found that the runners wearing the bibs belonging to M60-64 runners listed as taking first and third were in fact runners in their 40s. This is wrong and frankly disgusting to me. Anyway, that's the latest, and I don't think it will be the last time we have situations such as this.
I see and hear about more and more people giving their race numbers to other people without considering the consequenses. Right now, in my own age group, there is an inquiry going on about whether or not the person who won at the Soldier Field 10 really was that person. It goes much deeper than that. The major problem to me is the issue of medical treatment should a runner go down. If you have serious problems (cardiac for instance), and they think you're Person A with o-positive blood when you're really Person B with o-negative blood, it could be catastrophic. Then there is the whole liability issue from a race organizer's point of view if something happens to Person B who is wearing Person A's number. And, of course, there are the skewed race results which take days, even weeks to untangle. Runners who are serious in the CARA Circuit races and other big events do not enjoy losing to impersonators. There you have it. Bib sharing should be banned unless someone finds a way to legally transfer them before races begin.