Actually... the browser won't send a referer to a HTTP site if coming from HTTPS. From the RFC: http://www.w3.org/Protocols/rfc2616/rfc2616-sec15.html#sec15.1

Actually... the browser won't send a referer to a HTTP site if coming from HTTPS. From the RFC: http://www.w3.org/Protocols/rfc2616/rfc2616-sec15.html#sec15.1.3 http://www.w3.org/Protocols/rfc2616/rfc2616-sec15.html#sec15... "Clients SHOULD NOT include a Referer header field in a (non-secure) HTTP request if the referring page was transferred with a secure protocol." I wonder if Google will implement POST forms instead of GET to prevent caching of request-uri data by the browser as well as proper Cache-Control/Pragma/Expires headers to prevent caching of search results.