you don't seem to understand how this works, so ill explain it for you. google works as a spider. every searchengine does. it searches domains for links and tags. it indexes these tags to and matches them to a link list. when you search google, you pull up a list of links that closely match your search term. basically if i set my search engine to index to a depth of six, and all bitcoins sites had some random hash tag like "hashBTC1321ljwljaslsdjaflasorewralesfjlsadfjasdl99999999999" i could set the spider(search engine) to leave the domain, and it would find every website on the internet with that tag in its meta tag list.