I support these people who are keeping chickens in their backyards, and I think they're creating wonderful PR for the animal welfare movement. Chickens are cute and likeable creatures that children get along well with. If people start regarding chickens as companion animals, they'll be more inclined to reduce the suffering experienced by chickens on factory farms. As far as farm animals go, it's the chickens that I'm the most concerned about -- the suffering:meat ratio there is pretty terrible. (Veal calves have it really bad too.)
Also, I sympathize with the chicken owners' struggle against the stodgy homeowners' association types who want to prevent their neighbors from doing anything interesting.
(Picture from Cute Overload, of course.)