Surfing the web these days isn't the same as it was 10 years ago. And it's not just because there are less websites with HTML frames and 'under construction' GIFs. The fact of the matter is that everywhere you go on the web is being tracked, and the ability of sites and services to benefit from this is becoming the accepted norm. It's the lifeblood of companies like Google and Facebook, whose embedded elements allow any site to send data about your browsing habits back to the great data processing center in the cloud.
Ad networks have been doing this for years. It works through the creation of Cookies, those hidden temporary internet files that your browser creates which contain data about the websites you visit. An ad network like Doubleclick, for example, can read your Cookies on any site that has its ads, creating a partial profile of your web activity. But while this exchange has traditionally been anonymous, it's now more personal than ever thanks to social networks, which provide a direct link (called a URL referrer) to your private social profile on the web. Even so-called "anonymous" data tracking, which Google swears by, may not be so anonymous after all.
Fortunately, there are ways to fight back. One particularly user-friendly method is the browser plugin Ghostery.
It works like this: As you browse the web, Ghostery identifies elements from 3rd parties that appear on the sites you visit and gives you the option to block them entirely. Say you visit Motherboard.tv and click through to this very article. When the Facebook 'Like' button loads, the data of your visit would normally be automatically sent back to Facebook via the cookie it created in your browser. When Ghostery is active, it will tell you that Facebook (and anything else it catches) is accessing your data and give you the option of blocking those elements. It can find and quash spyware, malware and badly-behaving scripts too.
All of this is configurable from the plugin's menu, with links to helpful profiles of the various entities trying to gain access so you can make informed decisions about who you're sending your data off to. Ghostery also, somewhat ironically, can collect your usage data in order to help its developers better identify exploitative web elements. But this feature is thankfully opt-in only — a dialogue during the setup very implicitly states this option is dependent on the user enabling it.
While we wait for the people in charge to give us some kind of protection (don't hold your breath) in light of the growing trend of web tracking, Ghostery remains a good option for those who want to browse exploitation-free and also continue using various social networks and services. But like everything, make sure to read the FAQ before running around acting like you're protected everywhere.
Ghostery is available as a free plugin for Firefox, Chrome, Safari, Opera and (ugh) Internet Explorer.