This is slang for posing some question or problem that a “nerd” can’t help but solve, to the detriment of everything else they need to do.
It comes from the concept of “sniping,” shooting someone at long distance who dies before they even know what happened. To “nerd snipe” someone is to give them a problem that sweeps them up in finding a solution so quickly they don’t even realize what happened.
Why I Looked It Up
A friend used the phrase once to describe how he wrote a large software feature in an evening because of a conversation we had – “You nerd sniped me.”
Then I found this XKCD comic entitled “Nerd Sniping” which shows a game where an electrical engineering problem is left on a piece of paper in the street in an attempt to get engineers so distracted they get hit by cars.
One person exhorts the other:
C’mon, make a sign, it’s fun! Physicists are worth two points. Mathematicians three.