Tracking software seems all to prevalent now, most of it seems to monitor (allegedly) customer usage for commercial purposes. I remove stuff like this regularly using spybot or adaware ...
Interestingly, I don't do the lottery, so ignore all emails in that vein, but received one last week that cited I had won ... when I did do the lottery many years ago, it contained 4 of the numbers I would have chosen, which have never been published on the net ...
Derek