What's the deal with all those websites that have our site info?

I've noticed that when I run a search in Google/Yahoo under my domain name, I see a bunch of sites that are reporting stats, value, IP address, and other info regarding my sites.

How do I prevent these sites from reporting this information online? Is there an easy way?

You don't. whois is a matter of public record. You can purchase a proxy/private registration service through your domain seller.

I've always had private registration. These sites don't have my personal info. Some just have my domain name with certain stats like estimated value, popular keywords, etc...

One site even claims to have corporate info for my site and lists all these fakes names as the President, CEO, COO, etc...

Yeah, it's all BS and no one really takes any of this 'estimators' for any value.