Would Google and Yahoo Geo-Filter Adult Searches?

[MeatPounder]

I am in the process of adding a PICS label through Safesearch rating my sites as Adult, and ICRA labels doing the same to all my sites.
There has been a general agreement as to the adult webmasters duty to add some sort of labeling to their sites, and quite a discussion as to which method to use...one of the above for example, a simple meta tag, or even a completely new method.

Search engines have become a primary method of finding porn on-line.
You would probably be surprised at how many of my clients do not even use the address bar in their browsers anymore, but type all their URLs directly into browser search bars.

We have all seen in the news how Google, MSN, Yahoo and other search engines have been tailoring their results by geo targetting....a prime example is China.

Why don't we really push as an industry to have all the major search engines geo target their search results for porn related terms so that unless a web site has an adult tag, it will not show up in any search results from a United States based ip address? As far as what type of adult tag, the search engines themselves can tell us which to use.
Any other country that also wants such filtering of adult sites, could simply tell the search engines to do so. The major search engines have already complied with several such requests such as the above mentioned China...and Nazi related terms in Germany, etc.

As far as international webmasters, they would be free to do as they wanted, but if they wanted to show up in search results in the United States (and any other country that wanted this system), they would have to comply.

Sure this is not a complete answer by any means, but it would be a great first foot forward.