Ghostery sees the invisible web - tags, web bugs, pixels and beacons. Ghostery tracks the trackers and gives you a roll-call of the ad networks, behavioral data providers, web publishers, and other companies interested in your activity.
It can either report them or block them or log them to Ghostery for publication purposes.
Running Ghostery is quite informative. Going to the TV Guide listings found 32 trackers!
While TV Guide has a lot, almost every website has some although my Intranet site is clear.
Of course, there seem to be three trackers associated with this tumbler entry. In addition, to the privacy issues that are apparent, each one of these must do at least one HTTP request/response cycle leading to a slowing of the Internet experience.