Microsoft has teamed up with New York department megastore Saks for a big Christmas promotion, that, as well as a special sales area inside, includes Windows 7 powering the store's infamous Christmas windows displays.
As part of the window displays, Microsoft has set up a screen displaying a live Twitter stream, with posts hashtagged HolidayWindows automatically showing up on the display.
What Microsoft perhaps didn't account for though, is Apple-loving Twitter users taking advantage of the stream to promote their own pro-Apple and/or anti-Microsoft messages.
A quick glance at the #HolidayWindows stream sees it chock-full of such pro-Apple pithy missives as the brief "Get a Mac" that appears multiple times.
There's also the likes of "Get a Mac! Just follow the masses down to the Apple store. The one that looks like the Windows store... only way cooler", "Avoid viruses - get a Mac", and "Ignore Microsoft, you're not a PC, you are a human being. Get a Mac and feel human again".
As @mooseblaster says, this cannot end well.
UPDATE: It seems the whole stunt was masterminded by Mac fan site MacDailyNews, but appears to have taken on a life on its own now with pro-Mac tweets coming thick and fast, way outnumbering any Windows fans who have attempted to mobilise with a counter-tweet attack.