That's a good question - I'm not sure. It's about 10 feet from my door. Technically speaking I'm "responsible" for maintaining it under NY law, but I don't know if it's strictly private property. The city can (and does) ticket homeowners when something is blocking their curb if it's 1) a tortious danger to pedestrians (i.e. snow) or 2) interfering with municipal activity, like garbage pickup.

That being said I'm not really concerned about being ticketed because it happens so rarely. I'm more concerned about neighborhood appearance and being able to place my garbage in a consistent spot. For context, this is in an area which is more suburban than urban. Having a regular bike chained to a sign outside my door would be equally out of place.