I took Alice, my visiting mother-in-law, for a ride in the Avenues one day, heading to Hatch’s for a chocolate fix, when we stumbled upon a bicycle rack covered with knitting. The knitting encased the entire structure, kind of like a cocoon, in different-colored stripes and with various types of yarn. Alice had never seen anything like it. I told her we’re in the midst of a fad, with rogue knitters scurrying about under cover of night, knitting as if they were graffiti arti