Are you certain your online activities are private? Think again.

Not only are your surfing sessions tracked by websites, search engines and social networks, but often your Internet provider, Web browser, government and potentially hundreds of online tracking companies.

Whether it's to collect valuable marketing data or prevent criminal activity, everything you think you're doing privately in the comfort of your home is anything but private.

That said, there are a few ways to spend time online anonymously. The following are a few suggestions.

SMART SOFTWARE

How does Facebook know to show you ads for your local gym or supermarket? In part it's because your computer's unique Internet Protocol (IP) address, assigned by your Internet provider, reveals your geographical whereabouts. Even if your computer generates a different IP address every time you boot up or log online, this number (e.g. 220.165.119.12) can still tell your general location.

There are a variety of solutions that can hide your Internet connection, allowing you to remain anonymous while online.

Some are websites, such as free "online proxy servers" that conceal your identity. Simply point the Web address (URL) to the proxy server and surf right from its website (check out proxy.org for a list of great options).

Others prefer to download Virtual Private Network (VPN) software that encrypts your online sessions.

The browser-independent Hotspot Shield from AnchorFree (anchorfree.com), for example — available for Windows, Macs, iPhone and Android — channels all Web activities through a personal VPN and secures Internet communications by turning all HTTP traffic into the safer HTTPS (which is what your bank uses for a safe connection). There's an ad-supported free version and a beefier "elite" option ($29.95/year) with more bells and whistles.

Similarly, Tor is free software that defends you against Internet surveillance that threatens personal freedom and privacy. Short for "The Onion Router" — which gets its name for its "layered" approach to the encryption process — Tor (torproject.org) provides online anonymity as the software routes Internet traffic through a worldwide volunteer network of servers to conceal your location or online usage patterns.

USB STICKS

In some cases, software to encrypt your connection is kept on a USB drive — so you can remain safe and secure even when using a public PC.

SurfEasy Private Browser ($69.99 one-time fee; surfeasy.com) is a tiny USB key that fits into a credit card-shaped case to be kept in your wallet. When you plug it into a PC or Mac — be it your own computer or a public one — it instantly launches its own password-protected browser and you're good to go (no proxy or network settings to configure).

Your browsing session is handled through SurfEasy's fast and secure private proxy network. Your IP address will be masked throughout the session.

The company also has a new downloadable product called SurfEasy VPN that can protect computers, smartphones and tablets.

Also consider Tails (tails.boum.org), which can be downloaded and installed onto a USB stick to run independently of the computer's original operating system. Like SurfEasy, it lets you browse the Web anonymously — on virtually any computer — as all connections are channeled through the aforementioned Tor network.

BROWSER TWEAKS

Anonymous proxy software is a great way to mask your IP address online, but there is still plenty of information about your Web-surfing habits stored on your computer — which could also be viewed over a network, say, at the office, by your IT department.

At least it's somewhat easy to control your privacy settings directly in your Web browser, unless your company forbids non-administrators from making changes to your browser settings.

You can disable cookies — tiny text files stored on your computer with information about where you've been online, passwords and other info — and you should also delete your browser history to cover your tracks. All major Web browsers — such as Internet Explorer, Firefox, Chrome or Safari — allow you to delete your surfing history: Simply go to the Options or Settings in your favorite browser and you'll see how to do this.

You might want to turn off auto-complete or someone on your computer could type in a few letters in a search engine or Web address (URL) bar and any recent places you visited could fill in automatically. And don't click to allow sites to "remember my password" or someone could gain access to your private or financial information.

The easiest thing to do, however, is to see if your Web browser has settings for surfing incognito — most of the major browsers do today. By enabling these privacy settings, your browser won't save any history (and download history), search queries, cookies or passwords.

When it comes to your search engine, you could choose not to save your history. Google, for example, was recently ordered to make this easier for users, to avoid European privacy rules. You could also choose not to log into your Google account when using these services (or not use them at all) or you might want to install one of the free browser plug-ins that tell Google and other advertisers to back off.

Finally, you might have heard Facebook is going to start sharing Web-browsing history it collects with advertisers to display more targeted ads — yes, even on non-Facebook sites you visit. But you can opt out of this within Facebook's Privacy settings.