Why Google, Facebook continue to track you closely

Alexandru Catalin Cosoi, Special for USA TODAY | USATODAY

(EDITOR'S NOTE: Google is being taken to task for collecting personal information from Android users and forwarding it to app developers without asking permission. And Facebook has raised privacy concerns anew with the launch of a controversial "promote-and-share" service. In this guest commentary, Catalin Cosoi, chief security strategist at antivirus firm Bitdefender, explains why the tech giants are so eager to track where you go and what you do on the Internet.)

BUCHAREST, Romania -- Ever wondered why website ads seem to know exactly what you need, before you actually need it? It has to do with web trackers and their ability to monitor your every search query, clicked link or visited website.

It might seem like a scene from an old spy movie, but rogue web trackers could act like double agents that trade company secrets and sell your online profile to the highest bidder.

They can know everything from your shopping addiction to the kind of movies you like. Imagine being targeted by ads that try to sell you movie tickets at incredibly low prices or maybe your favorite brand of shoes at a discount. Would you really want that all the time?

No law clearly states how long web trackers can store your profile. Marketers can argue that internet information on you is not stored forever and as such, privacy is neither abandoned nor violated. Truth be told, only best practices and moral guidelines steer web trackers.

From a political standpoint, the amount of information collected is not held accountable and you will inevitably be served cookies, or you might as well stop browsing altogether. So, where does the line between intrusive and non-intrusive end, and when is your privacy and security at risk?

Imagine your online identity as your personal diary. Every time you write down some new experience, someone's watching without ever saying a word. After a while, it could use the collected information or sell it to a third party. You be the judge of how intrusive that is, but remember that's pretty much the way web trackers work.

In terms of security, browsers send a lot of data about your computer from your operating system -- whether the browser has Java or Flash installed, what browser ports are opened and available, and much more. In the hands of a cyber-criminal, this information could be the key to your laptop along with what secrets you may have stored in it.

But it can get much worst.

Web tracking can facilitate stealth monitoring of a target, which in some cases is known as industrial espionage. For example, linking an IP to the employee of a company and then analyzing his browsing history may give attackers clues about product development or marketing strategies. Knowing the keywords employees typed into search engines may reveal very sensitive data about their company.

If you're an editor at a newspaper and someone was able to track your browsing activity, he could intuitively know what your next story would be based on the online research you performed. Imagine that information ending up in a competitor's newspaper and hitting print before your research was over.

Although most web trackers don't usually collect this type of information, rogue websites could employ the same tracking methods to compile minutely detailed information about each visitor. The same tracking principles apply, with or without consent, to a regular PC browser and a mobile browser.

While some web trackers have a lot more to lose, from disclosing tracked information on you to third parties, this doesn't mean that others will be as equally self-conscious.

Catalin Cosoi is chief security strategist at antivirus firm Bitdefender.