The other day I got a link to a site called BlockShopper, which shows information about people buying houses in various neighborhoods around the country. They use public information, like name of buyer, the cost, and the address, but then they Google the folks and put more information, like where the person works, their photo, their resume, etc. It's pretty strange and weird.
I guess the idea is for home buyers and owners to see what sort of people are buying, as their FAQ says "For home buyers, we built BlockShopper to be the ultimate objective resource, meant to give you the intelligence edge. Before you make the biggest purchase of your life, you cannot afford not do due diligence here." Seems to me that there could be a possibility for something negative to happen.
The site's FAQ says they won't take information down if requested, and they've been sued by a law firm, though the suit seems kind of specious - they sued the site for trademark infringement, and BlockShopper settled.
I guess the site is legal, but it's pretty creepy.