The neighbor parked there because he's too lazy to shovel the snow in front of his own house, where an empty, but unusable parking spot is also available, and has no qualms just sailing into the tidily shoveled spot in front of your house, so that you have to shovel in front of his house too when you return.

The city recognizes that situation as a valid complaint and will take action, and that's the end of it. It upholds the concept of parking being associated with adjacent residences, even though it isn't owned by them.