In the US, privacy isnt an issue of self-importance, but a an aspect of a constitutionally protected right. An opt-in service is great, but many are assuming that outside of this feature, your searches are private. This isnt new, just a feature Google decided to offer since they have been storing this info anyways, as do the other search engines.
The use of the feature isnt the first part of the opt-in. That commences when you use the search engine to begin with.
Bill, comparing resumes isnt the point here. Putting this feature and privacy issues into prospective is.