Guess I shouldn't have put "Property rights" in the title, after today we don't have any.
One more thing, a lot of the "blighted" nieghborhoods are the ones that have housing that lower income and starting families can afford.
Try this scenario on for size:
A government bank in China buys Unocal and takes your property to build a refinery where you live.
Theoretically, a foreign government could take your land!