If you are really bothered by being linked to your previous search history, simply change to a different ISP. Make sure you delete all your cookies obtained while under the old ISP.If you are going to go to all that trouble, make sure you do ALL your questionable surfing over Tor, or I'd suggest a VPN/proxy service like Ivacy. VPNs are great, you can run Tor over them, and torrent to your hearts content with Ivacy keeping no logs of your traffic.But seriously, unless there's already black helicopters hovering around your flat, I don't really think you need worry about it.