When this all started, no one envisioned ad networks and data companies aggregating all this personal information, or even that search terms would be a central part of the Internet.
So now that we know what is going on, why allow this personal information to leak? As far as I can tell, the only reason is so Webmasters can do better at Google SEO. And that reason can be wholly mitigated through the use of Google's Webmaster Tools.
No, Google's webmaster tools only provide a sampling of the data. We used to provide info for only 100 queries. Now we provide it for more queries, but it's still a sample: http://googlewebmastercentral.blogspot.com/2010/04/more-data...
Please don't make the argument that the data in our webmaster console is equivalent to the data that websites can currently find in their server logs, because that's not the case.