not sure if it is the same were you are, but some streets you are not allowed to park on the curb. one area we lived in, would get a parking fine for being parked on the side of the road out the front. yet here, there is a massive truck parked on the side of the road every day and night, taking up half a lane, yet there hasnt been an issue as yet (except near misses with oncoming cars due to lack of room) could you call and see if there is a legal requierment in regards to street parking? if it is near a corner they have to be a certain distance. ETA, a parking fine or warning could get them to move it and they wouldnt know who it was if they dont seem like the nice neighbourly type.
HTH