I don't like to circulate stuff that I can't verify, but given that the source which is circulating this is someone I trust -- a former senior producer at NBC News -- I don't feel quite so bad about putting it out there.
According to the person who originally uploaded this video to YouTube -- a voter in Pennsylvania -- here's what happened:
"I initially selected Obama but Romney was highlighted. I assumed it was being picky so I deselected Romney and tried Obama again, this time more carefully, and still got Romney. Being a software developer, I immediately went into troubleshoot mode. I first thought the calibration was off and tried selecting Jill Stein to actually highlight Obama. Nope. Jill Stein was selected just fine. Next I deselected her and started at the top of Romney’s name and started tapping very closely together to find the ‘active areas’. From the top of Romney’s button down to the bottom of the black checkbox beside Obama’s name was all active for Romney. From the bottom of that same checkbox to the bottom of the Obama button (basically a small white sliver) is what let me choose Obama. Stein’s button was fine. All other buttons worked fine."
This could be a hoax. It could be a very serious miscalibration. Or it could be something unimaginably insidious. Regardless, I have a feeling you'll be seeing this 18-second clip quite a bit in the coming hours and days.