Someone In Carroll Gardens Harbors A Strange Grudge

Who in Carroll Gardens is graffitiing parked cars by writing "Parking Pig" on them with a wax pencil?
Reader Alix took the photos above yesterday evening and wrote the following:
Tonight [Tuesday], walking home on Degraw from Court Street, I saw two cars had been graffitied with the message "Parking Pig" written in some kind of waxy pencil. The message caught my attention because the same words were scrawled on the hood of my car a few months ago. And a month or so later-- another car on my block was also vandalized in this manner. So this is the third time the perpetrator has singled out cars for this attack. (Perhaps there have been more incidents and I missed them.) It's strange since cars park and move so frequently in my neighborhood that it's really not hard to find parking! And annoying because the waxy material is hard to remove. Maybe your readers will have some insight into the nature of this peculiar grudge.
Peculiar indeed. Why would someone do this? And who is this person?