What if your neighbor took pictures of your family?

Imagine the scene - nice warm evening - very still outside, with only the sound of crickets to break the silence. Great weather to enjoy sitting outside, as one of the residents was doing. Once it got dark, though, something interesting happened. The neighbor next door turned out their inside lights, then came out onto their deck and took pictures - not just 1, mind you, but several. It happened again a couple of weeks later. Now, I have some idea why the guy next door would take pictures of some other guy's wife while hiding in the dark, but it's not prudent to publish them here. What did the resident do? Asked the guy why he did it, asked for the pictures and asked them to stop. They refused to respond at all.

Wonder what the motivation was and where the pictures ended up? Unfortunately, while most would view their actions as reprehensible, it ain't illegal to hide in the dark and take pictures of someone else's family. Oh, and the HOA? No stance.