Everyone is up in arms about the NSA spying on private communication, but did you know that most of the websites you visit are tracking your online activity in one way or another? In the vast majority of cases, websites tracking your activity are using it as market research or as a way to target the advertising that they deliver to you. That doesn't make it any less unsettling, however, and has encouraged the rise of anti-tracking plugins and other ways to stop the tracking. The websites might just want to make a buck, but tracking your every move online is a major privacy concern. Here's a few ways how websites keep their eyes on you.

Cookies are one of the most common tracking methods

A cookie is a small file that contains information for the website's use. They are used in a wide variety of ways outside of tracking your activity as well, such as storing login information, whether you have visited before, and to keep track of site preferences. Websites that use cookies are required to disclose this fact, so as long as the website is on the up and up you will know whether they're using cookies or not. You can clear most cookies from within your browser, or using a private browsing mode such as Incognito mode in Google Chrome. There is a type of cookie that cannot so easily be deleted called a supercookie. These are cookies that aren't just stored within your browser, but in multiple areas so you have to clear all of these locations at the same time or the cookies populate automatically.

An IP address is a unique number that represents your computer on the Internet

IP tracking is commonly used on website forums and other sites that are interested in seeing whether someone is a new or returning visitor. For forums that have rules against multiple account, IP addresses can be used to determine whether someone is breaking this rule. If you don't want someone knowing your IP address, you can use a proxy service. You browse websites through the proxy, which makes you appear to have a different IP address from various parts of the world.

Disqus is a commenting plugin used for WordPress, Tumblr, and many other blogging and content management systems

It's a universal login, so you don't have to create a separate account for each site that you want to comment on. However, this means that Disqus tracks information such as your posting history, IP address, and web browser version. They also put the comments on public profile pages for each user.

Facebook Connect uses the Facebook API to provide a universal login for websites that support this feature. It connects the site and Facebook so you don't have to create a separate login, but this means that you're providing personal information from your Facebook page to third party websites, which may include more information than you're comfortable with. You can only avoid the tracking of the third party service if you do not subscribe to them at all. It is up to you.

If you want to be as careful as possible with the information that third parties have access to online, we would recommend a plugin such as Do Not Track that eliminates major tracking methods from affecting you. This plugin blocks social buttons, ad network tracking, cookie placement, and provides full information on the methods each site is using to track your online activity. The websites might just be using this information for advertising purposes, but that doesn't mean you aren't entitled to privacy.