koan - 7:26 am on Dec 30, 2010 (gmt 0)
If you search the domain name of a site that contains adsense ads with blekko, it displays a link called "adsense" in the results and if you click on it, it'll display all the other sites it knows using the same adsense pub id. I know some other sites provide this service, but at least people have to pay for it so it's not public information for any casual visitors, or worse, people who will reuse that info in some mashed up, scrappy site.
Considering this is rather personal information, I'm deliberating blocking this new search engine in my robots.txt file as it isn't really bringing any traffic, it's using my bandwidth and it's already pushing some boundaries regarding my privacy. As a webmaster, I know we should be open to new search technologies and give a chance to new comers, but what have I to gain really by allowing them to crawl my sites so far if the negatives outweigh the positives?