He walked over, explained that he was extremely upset with my tweet about eBay, because his wife works there, and told me to be careful about what I say in public.
Then he took a deep breath, I assume to calm himself down, told me how he found me, said he was unfollowing me on Twitter. Then he left.
I haven't quite had the location-by-metadata gem, but I do get people tracking me down at public events or finding out my business number and calling to harass me with some insane ramblings, or emailing me based on some very confused interpretation of what one of my sites does.
To anyone interested in such events I would highly recommend "The Black Swan" The Impact of the Highly Improbable by Nassim Nicholas Taleb.
It never amazes me what you can experience, if you are living in a large City or get involved with a large group of people. When I was doing National Service, I once drove to the Hospital, about twenty, 18yr olds suffering from "nocturnal enuresis" (http://en.wikipedia.org/wiki/Nocturnal_enuresis). It is a very uncommon event in adults <0.5%.
To be fair, The Black Swan doesn't talk about a black swan being rare. The point is that until black swans were discovered in Australia, everyone in the (civilized) world were completely convinced that swans could only be white. Black swans weren't rare, they were inconceivable because it was so far outside expectations that no one considered even the remote possibility of non-white swans.
The Black Swan doesn't talk about rare events, it talks about the danger of not considering that which is so highly improbable as to seem ridiculous, such as the possibility of non-white swans.
In other words, the frequency of black swans wasn't 1 in 1 million swans pre-discovery of Australia, it was zero.
I'm sure you know all of this but if you haven't read the book I do think it is worth your time.
Oh, you don't need a big site for this stuff to happen. These things aren't even close to one in a million. I've had tons of these and even weirder running sites with only 10-20,000 users.
Terry Pratchett was fond of saying that one-in-a-million chances come true 9 times out of ten, but I believe in that he was referring to fiction and not internet crazies.
Having been developing on a high traffic site for a while, these things are very on point. We always joke that our inputs are superpositions: all combinations of inputs are possible into our site, due to the sheer number of people visiting a day, and the # of crazy people who will attempt to inject nonsense into their POST requests.
Turns out he was angry because I posted a tweet three weeks earlier about hating eBay.
There are some crazy people out there, for sure.