This is a story from Trey Harris, who was in charge of the e-mail system at the University of North Carolina. He was contacted by a department chair who claimed that no one in his department could send e-mails more than 500 miles.
Before you object that, you know, that's not how e-mail works, let me assure you that not only was it true, but Harris managed to figure out what was happening. Here's an excerpt:
"What makes you think you can't send mail more than 500 miles?"
"It's not what I *think*," the chairman replied testily. "You see, when we first noticed this happening, a few days ago--"
"You waited a few DAYS?" I interrupted, a tremor tinging my voice. "And you couldn't send email this whole time?"
"We could send email. Just not more than--"
"--500 miles, yes," I finished for him, "I got that. But why didn't you call earlier?"
"Well, we hadn't collected enough data to be sure of what was going on
until just now." Right. This is the chairman of *statistics*. "Anyway, I asked one of the geostatisticians to look into it--"
"--yes, and she's produced a map showing the radius within which we can send email to be slightly more than 500 miles. There are a number of destinations within that radius that we can't reach, either, or reach sporadically, but we can never email farther than this radius."Read the whole thing here. There's also a FAQ if you want more technical details.