Stay warm, NYC

I've been walking to work a lot these days; Astoria to Midtown is only 3 miles, and if it's neither too cold nor too drizzly, I figure I might as well enjoy it before winter descends fully. This morning, I was delighted to find someone had covered part of the railing of the Queensboro Bridge with red crocheted scarves, accompanied by a note that read, "Stay warm NYC. Merry Christmas! Please, take a scarf." I didn't grab one, but the random act of artsy kindness warmed my heart. Anyone know who's behind this?