That's true but - -
tracking cookies get generated from the host side and delivered with the response to the first request.
But, in privacy mode, those get dumped when you close the browser, while no current history is retained. I suppose, it's not perfect, but it's a lot better than going in blasting with IE in its stock form.
I've even run into the, "FBI virus pages", claiming my IP had been logged, and I had to pay money. With NoScript running, I just clicked the window closed and went on my merry way.
http://www.fbi.gov/knoxville/press-releases/2012/internet-scam-warning-reveton-ransomware
Boatloads of people, are pissing and moaning on how to get rid of this ransom-ware.
It is indeed indicative of the potential havoc that cross site scripting can wreak while tracking you, and how effective script blocking can be at eliminating it.
Besides, anyone who uses Chrome has already acquiesced to being tracked by Google. Is anybody really naive enough to believe that Google would allow its own, "googleanalytics" script to be blocked?
As for using Yahoo, why bother? On any query you'll get as many as 10X the search results from Google. Those you just block with Firefox.
(True, FF & Google are true, in bed together, but I'm not sure they're enjoying it. Just going through the motions, so to speak

).
@
jobeard If I'm incompletely informed, or incorrect about any of this, feel free to correct or further enlighten me.