[zencycler]

So why not just plant some shrubs, or put up a nice neighborly fence, or better yet ... build a wall!

[jazusamo]

Absolutely...If they stay neighbors I’d recommend the wall, a high one.

[CaptainK]

I live next door to a house in disrepair i.e a dump. I put up a fence and have trees and bushes that block the view.

That's all you need to do.

[Cecily]

Some options: http://www.walterreeves.com/landscaping/plants-for-screening/

[Madam Theophilus]

Perhaps the community regulations forbid a permanent structure, hence the pile of yard debris. It’s easy to explain if someone asks (I’m so sorry about this, but you know my legislative schedule has been soooo busy this term. I’ll take care of it as soon as I can.) In the meantime, it conveniently blocks the neighbor’s line of sight into his yard. And should the neighbor take matters into his own hands and clears it away, it’s easy to replace!

[Yaelle]

Only good thing about California. Every property has fences or walls. We can’t even imagine life where your yard is undefined. It’s creepy and agoraphobic to us.