We get them frequently down our rural road, and we usually report them to the council (Auckland) who are pretty good at getting a contractor to pick it up.
We got some feedback from the council a while ago that they successfully prosecuted someone over it after finding identifying information in the pile. It turned out to be one of the commercial rubbish disposal companies, they literally drove their truck down the road while someone in the back chucked all the rubbish out onto the road. Didn't even bother putting it to the side.
A few years ago we had the road partially blocked by a massive tree stump - must have been 2metres diameter and weighed a ton. It was chained to a concrete power pole which took some head-scratching to figure out why. The way they dumped it off their truck was to chain it to the post, then jump in the truck and drive off ...
One of these days I'll get one of those cheap battery powered trail cameras and hide it up a tree to catch these people. The council says photo evidence is usually need for a successful prosecution.