Ghostery is an add-on to FireFox (and other web browsers) which stop sites from tracking users as they surf the web. Installing it depends on which web browser and which version is being used. A good place to start is either tools, extensions, or add-ons. Once installed and the browser is restarted, Ghostery will go through three or four configuration screens. The last screen lets the user select which tracking cookies/bugs to block.
One of the options is to let the user know which cookies/bugs are being blocked. My record is seven or eight sites. The average is around three. If you are like I am and want to maintain at least a minimum of privacy on the net, this is a good place to start.