the concept of the trusted web

I wrote some weeks ago, that cryptographic signing mechanisms would be a good solution for getting spammers and vandals of from Wikipedia. The more i think about this idea, the more appealing this idea sounds to me. Today at showering i had the following idea.
Many problems can be solved by overlaying the web of content with a web of trust. Okay, take google as an example: The algorithm for google search don´t obey the worth of the information itself, it´s only aware of the link topology of the internet. Okay, this is an natural limitation of automatic indexing, as computers need an algorithm to classify, they don´t understand the content, so they have no idea of the content. So they cannot speparate usefull content or SEO.
Now think about the following concept: