Google offers all sorts of interesting information. And as David Leonhardt points out in today's New York Times, the information is getting more fascinating all the time.
On a related note, when I first started blogging, I discovered that I can learn which site referred a reader to this blog. For example, I can find out whether someone came here by clicking on a link on another blog or by way of a google search. Most surprisingly, if you came here by way of a search engine, I can see what search terms you used to find us. Although I can't see your identity, the revelation of your search terms can be quite interesting.
On one occasion, I was amused to discover that someone came to legalethicsforum.com after typing "Andy Perlman" into google. Again, I couldn't determine who conducted that search, but the use of my nickname "Andy" narrowed the list considerably. One could imagine a set of terms that could make it possible to identify the particular person doing the searching. For example, imagine a lawyer conducting a google search that contains the names of litigants as well as other specific, revealing facts. It's possible that, if the search leads to a web site, the owner of that web site could discern the identity of the lawyer and even what the lawyer is thinking about a particular case. Although the chances are still remote, changing technology is making Internet investigations somewhat more hazardous.
There is also a non-legal dimension to the ethics issue. Did you all know that I could discover your search terms if you came here via a search engine? If not, do you care? Does this feel like an invasion of privacy, even though I don't know your identity? Should we make clearer that we have access to this sort of information and that we look at it? Or is the lack of privacy on the Internet so obvious to everyone that this issue is really a non-issue?