Ask HN: Is it time for a privacy rating system for the web?

A simple rating system for the privacy of a particular website. Perhaps in the form of traffic lights as seen for calories on food products in the U.K. Any way which makes it easy for everyday users.

A system such as this could have a very positive effect on making the layman more aware of privacy. It may also act to discourage sites from those "Red" ratings.

There are efforts such as Mozilla Collusion (https://www.mozilla.org/en-US/collusion/) which acts as a plugin. The problems with these systems is that is puts the onus on the users and totally excludes non-expert users from privacy.

What are people's thoughts/ideas on implementing a web wide system such as this or are there any efforts to do so which I am unaware of?