There are at least a couple of "don't track me" search sites which get their search results from Google. (I'm thinking of Scroogle.org and StartingPage.com). [Note: I don't know exactly how StartingPage.com works; Scroogle.org apparently "scrapes" Google search results. I assume StartingPage.com does something similar.]
However, I notice that neither StartingPage.com nor Scroogle.org return exactly the same results as Google.com. I tried searching, for instance, for "boingboing", and while the top three hits were the same for all three services, after that there was some amount of variation.
StartingPage.com also has an "image search", which at first blush appears similar to Google's. However, I get essentially completely different results when using StartingPage vs. Google image search (in contrast to the regular web page search, where at least the results were somewhat similar).
So I'm just curious, if StartingPage and Scroogle are scraping Google for search results, why the results are not identical?
Edit (5-Feb-11):
Some additional weird data regarding StartingPage (from http://www.boingboing.net/2011/02/04/startingpage-now-ret.html#comment-1018293):
In the book Javascript For Dummies one of the 5th Wave comics shows a woman being introduced to a natural language programming expert. She says something like, "Nice to meet you." and he says "Glorsplitz."
If Starting Page is just acting as a proxy and passing the info directly from site to site then we should get the same results:
Starting Page: Web Results 1 - 4 of about 4 for Glorsplitz (0.03 seconds) Google: About 1,310 results (0.06 seconds)
How about another semi-random search term? The anime Azumanga Daioh has a girl named Chio as its main character:
Starting Page: Web Results 1 - 10 of about 2,530 for chiochan (0.03 seconds) Google: About 38,800 results (0.09 seconds)
So why the difference?