Problem Neighbours

Does anyone have a good idea on how to deal with problem neighbours?

I understand that everyone is suffering from the massive amounts of snow that we have received in Southern Ontario this year. However, there is a decent way to deal with it, and then there is my neighbour's way to deal with it. For some reason the individuals to the north of me, have decided that our lawn is to be the dumping ground for ALL of the snow from their driveway. The mountain that they have created on our lawn has covered and seems to have killed one of the trees at the front of the house, as it is bent literally in half and buried in the massive mound. Due to the size of the snow pile, a few storms ago there were several "avalanches" - i.e. the neighbours continued to pile the snow on the pile closest to the house and the snow came crashing down covering our steps and front landing. A few weeks ago, I decided it was time to ask for some consideration from the neighbours and perhaps they could start moving their snow onto their own (virtually empty) lawn or at a minimum, take it further down the driveway so our front entrance wasn't blocked from their deposits. My plea was met by bitching and whining about "what are we supposed to do about it". I left, came home and had a break down. The next day, I was looking in the backyard and found that they decided to shovel the snow over the back fence and dump it into our backyard now. That's the neighbourly thing to do isn't it?
Frustrated and upset, I have been trying to be civil...my only saving grace being not seeing their faces outside for the past few weeks. That was until last night...
Exhausted for not having slept well over the past week, I went to bed early - 10:30 pm and managed to fall into a deep sleep. In the middle of a dream, I was interrupted and had visions of a snow plow driving into the house. Startled, I awoke to determine that it was actually someone using a snow blower in the driveway next to the bedroom. Snow and ice pellets were being blasted directly at the bedroom window. What time was it? 12:10 AM!!!
Angered, I took the time to put on my robe, flipped on the light and proceeded to the window to open and scream a piece of my mind to the ass doing the snow "removal". My plan was interrupted by the ass in question shutting off the snow blower prior to me making it to the window. By the time I had the blind up and the window open (was a challenge as it was frozen shut by the ice and snow from previous snow blowing instances), the mystery ass was making a quick departure down the driveway.
Quick to move, I bolted for the front door, but wasn't quick enough. The ass had made it to his truck and was driving quickly up the street. BUT, he backed into a driveway about 4 houses up and turned off his lights. I was shocked now thinking that this was another neighbour of mine disturbing my sleep and contemplated throwing on some boots and hiking up to have words. Perhaps a minute after the truck backed into the driveway, the lights were back on and he bolted up the street and out of sight.
Blood boiling and having been jarred from an unconscious state, I had some difficulty wanting or being able to fall back asleep. I was lying in wait for the clown to return so I could pounce and phone the police for noise violations, but the person never returned. After a brief, uneasy sleep, I awoke and peered outside. The snow blower remained in the same location in the middle of the driveway as where it had been abandoned less than 7 hours earlier.

What is the cause of some people being so ignorant and inconsiderate? And more importantly, does anyone know how to reason &/or deal with people like this? Ideally, I would like to have a civil relationship with them, and avoid any sort of bad blood or potential retaliation...WHAT CAN I DO?

Tired and defeated,
C.R.