After a bit, you decide you’re done and continue surfing, only to find that ads for the site you left show up everywhere you look. It gets really annoying. It’s worse than advertisers just tracking you online, though. They’re building a personality profile that they can sell to other advertisers and third parties. So much for privacy. The good news is that you can stop them. Before I get into the steps for stopping them, let me tell you how they’re tracking you. In a word: cookies. No, not the chocolate chip kind. I don’t think as many people would mind if that was the case. Cookies in this context are small files almost every website saves on your computer. The files store your settings and preferences so that you don’t have to re-enter the same information over and over. These “first-party” cookies are usually harmless. However, there are other types of cookies called third-party cookies. These are the ones that spy on you and track you from site to site. So, for example, if you visit a home decorating blog, the third-party cookie will record your visit. Then you might visit another website and see advertisements related to home decorating. If this seems a bit creepy to you, you’re not alone. Lots of folks are getting fed up with snooping third-party cookies. It’s not just advertisers tracking you, either. So, let’s put a stop to it. To get rid of the third-party cookies you already have, grab a cleaning program like CCleaner. It will offer to clean up the cookies on your hard drive, and it can target just third-party cookies. You can also just wipe out all your cookies and start over, but that can make sites you use often a little less friendly for a while. You’ll have to log back in and update any settings you had in place. Once the third-party cookies are gone, you need to change your browser settings to keep them away. For Internet Explorer, click on the gear in the top-right corner and select Internet Options. Go to the Privacy tab and click the Advanced button. Check the “Override automatic cookie handling” option, and then set “Third-party Cookies” to “Block.” Click the OK button. In Google Chrome, click the three-lined icon in the top-right corner of your screen and select Settings. Under the Settings section, click the “Show advanced settings” link at the bottom. In the Privacy section, click on the Content Settings button. Under Cookies, check the “Block third-party cookies and site data” option and click Done. For Firefox, click the three-lined icon in the top-right corner of your screen and select Options (PC) or Preferences (Mac). Go to the Privacy tab and under History, set “Firefox will” to “Use custom settings for history.” Then set “Accept third-party cookies” to “Never.” If you use Safari, third-party cookies are turned off by default, but it never hurts to double check. Pull down the Safari menu and select the Privacy tab. Choose the option to block cookies from third parties and advertisers. Blocking third-party cookies shouldn’t have a noticeable effect on the sites you use. However, if you notice a site isn’t working properly, go back into your browser’s cookie settings to make an exception for that site. Don’t let snoops see where you’ve been online. Here’s how to put your browser in full privacy mode.