Acronym for
There Is No Such Thing As Coincidence.
Often used in conversation in a semi-ironic, invocation-of-conspiracy theory sort of way, in answer to a claim of something being a coincidence.
example:
"The hard drive crashed just as I was about to do the backup. What a horrible coincidence."
"TINSTAC."
I'm not sure where this originally comes from. It seems like a Robert Anton Wilson thing, or some military folklore, perhaps, akin to gremlins or FUBAR. But suprisingly, the acronym does not show up very often when searching the web, though the phrase itself is a little more common. Perhaps they are supressing any mention of this idea. hmm....
update: I suspected this, but had to confirm, and now I have, that the acronym, at least, seems to have actually originated with 2 of my friends, UWI001 (known as Mumonkan here) and UWI014, of UnderWorld Industries. However, I have also located a computer in australia named "tinstac". coincidence? I don't think so....