The Office of the Privacy Commissioner of Canada (OPC) has just released a report entitled What an IP Address Can Reveal About You.  The report presents findings from an analysis conducted by the OPC's Technology Analysis Branch examining the privacy implications of IP addresses and other basic ISP subscriber data.  

In the report, the OPC stated that "conducting searches using the IP address ... often reveals a detailed profile of an individual's activities" and that "[t]his information can be sensitive in nature in that it can be used to determine a person's leanings, with whom they associate, and where they travel, among other things."