There's the recent Canadian case of a "pirate ship" treehouse which was visible but attractive.

The architect dad had asked for a building permit from the city beforehand. He was refused: they don't issue building permits for treehouses, they told him. A treehouse doesn't need one.

So he built the ship-shaped treehouse, complete with rows of cannons along its cedar-shake sides, for his two little boys to enjoy. City officials who came by while he was building it, didn't say boo. But the next-door neighbour's window faced right onto it, so eventually she complained to the city, which then did a formal investigation and ordered the dad to demolish it.

The family went to court, and lost. The two year old pirate ship tree house was torn down this September and auctioned off for charity.

Pity he didn't screen it better from the nearest neighbour. Sigh.