How to Protect Your Privacy When You Willingly Share Your Computer

When a friend wants to borrow your computer to check her email, she can stumble onto embarrassing information about your life without even trying. Maybe you secure your passwords or encrypt important files, but do you log out of Facebook every time you leave your personal computer? Or your email? Your computer knows an awful lot about you, and it's perfectly willing to share unless you tell it otherwise. Fortunately, there are plenty of ways you can protect your digital privacy in meat space. This guide will show you how.

The Web

Most of what we do is on the web these days, so that's where we're going to start. First we're going to take a look at some of the simple things you can do to improve your privacy and then the more extreme measures you should probably ignore.

Regularly Use Private Browsing

While the general assumption is that private browsing sessions are for porn, it's actually useful for much, much more. For example, many sites keep you perpetually logged in as a convenience—but the cost is that anyone at your computer can access your account. Most popular sites prevent any major account changes without verifying your password first, but that doesn't stop people from prying into all kinds of information you'd prefer were kept private.

Ever have anyone snooping around your Facebook account? Doesn't feel good, does it? If you really want to avoid snoopers, relegate your Facebook usage—and social site activity in general—to a private browsing session. Because you won't be signed in to Facebook in your regular browsing session, this will prevent Facebook's single sign-on feature from allowing you (or anyone at your computer) to log in to any other sites supporting it. Basically, the fewer sites you're logged in to the less you have to worry about someone getting into your account information when they have access to your machine. This comes with the inconvenience of manually logging in every time, but that's a price worth paying if you want certain activities and access to disappear without a trace.

Re-write Browsing History

Private browsing is great when you remember to do it, but sometimes you forget and sometimes you don't realize you want a piece of history removed until it's too late. Whatever the case may be, it's easy enough to wipe out a selection of items or absolutely everything. With most browsers, the shortcut you'll want to remember is Control+Shift+Delete (or Command+Shift+Delete on a Mac). This will quickly bring up settings to clear out your browser history. The newest versions of most browsers will allow you to select a time period to purge (such as the last hour, day, week, etc.) if you don't want to get let go of everything, but you can get even more specific by just choosing "Show Full History" from your browser's History menu and deleting individual items.

Remove Autocomplete Suggestions in Text Inputs

So your history's safe, but what about when your friend puts their cursor in your search box, starts typing, and the browser automatically offers to fill in the blanks using terms you've previously typed in? You can selectively rid yourself of embarrassing autocompletes in text inputs by highlighting an autocomplete option and pressing Shift+Delete.

Hide Embarrassing Recommendations

While Netflix inadvertently outing lesbians is on the extreme side, you've probably watched a few movies and purchased a few products that you'd rather not share with everyone you know. If that "accidental" rental of Madea's Adult Vacation or the Preparation H you bought last year just won't stop the unwanted recommendations thateveryone can see, you're not out of luck. It's possible to take your embarrassing product history out of the public eye.

Amazon

For Amazon purchases, all you have to do is sign in, access your account, and scroll down to the bottom of your options. There you'll find a choice called "Improve Your Recommendations." Click on it and you'll see your entire product history—but with a wonderful little checkbox to the right of each product: "Don't use for recommendations." Tick it and you'll stop getting those untimely recommendations for home pregnancy tests, or whatever is causing you public grief.

Netflix

Netflix isn't quite so simple, unfortunately, though there are things you can do to improve your situation. If you simply want to remove specific recommendations, all you have to do is click the "Not Interested" button beneath that recommendation. You can also do this for movies you've watched if you don't want them contributing to your recommendations. In the event you've forgotten to do this to a bunch of movies, you can always go to your account page, choose "See movie rating history," and show your disinterest in as many titles as you want.

None of this solves the problem of keeping someone out of your queue, however. While there is no simple solution to this problem, you have two possibilities: 1) sign out of your account when you're not using it, or 2) manage multiple profiles. Presumably you know how to sign out, but if you don't know how to create and use Netflix profiles it's pretty easy to do. From your Netflix account page, click "Account profiles" and then click "Add Profile" on the next page. From there you'll be able to create a new identity and handle all your private activity from that profile while managing your public activity from your existing profile. If you want to be extra sneaky, make up a fake name for this new profile and if anyone sees the embarrassing movies you've been renting, you can just say you let your friend use your account. It's not under your name, after all, so it's pretty believable.

Extreme Methods

All of the above methods are pretty simple and easy to manage. If you're incredibly paranoid and want to be as private as possible, however, there are more extreme options. You can disable cookies, your web browsing history, and always browse privately. When you're done with a browsing session, you'll want to immediately quit your browser as some files may be cached until you do. You may also want to disable Flash, as it operates somewhat independently of the browser. Basically, turn off everything. Don't sync anything. Don't save passwords. Don't use anything that will make your life more convenient. This is extreme behavior, and if you're in a situation that requires it you should seriously consider getting yourself out of that situation, but it's worth noting that there are plenty of ways to avoid saving any part of your browsing session locally to the computer you're using.

Your Desktop or Laptop

The obvious, easy solution is password-protecting your machine every time you step away from it, but that comes with its own set of disadvantages. Primarily, it implies that you don't trust anyone and have something to hide—which can make snoopers unnecessarily paranoid. It also means your machine isn't accessible on the network (unless you set up wake on LAN). Nonetheless, a password is often the best option. If you don't know, here's how to password protect a Windows computer or a a Mac. There are a few more creative and specific options, however, so read on if you're looking for alternatives.

Create a Doppelganger Account

Chances are you have your own laptop for your own use, but that doesn't mean you'll be the only one using it 100% of the time. Sometimes a friend will want to use it for a minute, borrow it while you're away, or just snoop when you're not looking. Locking your computer with a password often isn't enough in these situations, as friends aren't borrowing your computer to get stuck on a password screen and snoopers gonna snoop (which is to say, if they want in they'll find a way in). What can you do? Create a doppelganger account. This means you create a second account on your computer, under your name (just add your middle initial or something to make the account name unique), that you can switch to when you hand the computer over to someone else. This way you can have your private account locked for your own use and a "clean" doppelganger account available for everyone else. Just be sure you don't give this account administrative privileges of any kind or access to your other account's files. This method can mislead snoopers and keep anything your friends do isolated from your main user. Plus, thanks to fast user switching, it's pretty quick as well. While not foolproof, of course, this tactic provides the same security as password-protecting your machine with a few added bonuses.

Alternatively, if you don't want to mislead anybody, you can simply create a (or use your existing) guest account for virtually the same effect. A guest account is also locked down far more than a regular account, plus, if you're running Mac OS X, any files that were created while the guest account was in use will be deleted as soon as the user logs out.

Create a Private Account

In what's basically an inversion of the previous tip, you can create a private account that you can use for activity you want to hide. The Mac OS X guest account feature is excellent for this scenario because it deletes everything you do when you log out. On the other hand, you may not want that. If you want to create a regular account, you can always make up a fake name and attribute it to a friend. This is more believable than the Netflix example because creating an account for a friend doesn't mean the friend has to be local. Creating an additional account can just mean you're providing a friend with remote access to your computer. However you go about it, isolating your private data is a great way to keep it out of the public or away from prying eyes.

Hide Specific Folders and Files

If you don't want to lock down everything you can just encrypt or hide specific files. One of our favorite methods in Windows is hiding files inside of other files (check out the video version here), but there are plenty of other options. Mac users can download
Cryptor for individual file and folder encryption.

Your Smartphone

Smartphones are the newest technology creating a need for a privacy lock down so your options aren't quite as plentiful. That said, there are still a few things you can do on the various platforms.

Password-Protect Your Device

iOS

There isn't much you can do on iOS other than add a password. On the plus side, this is very easy to do:

1. Open the Settings app.
2. Tap General.
3. Tap Passcode Lock.
4. Enter your desired four-digit passcode.

As far as we can tell, jailbreaking won't provide you with a means to secure your phone any further. Fortunately, a passcode should be enough to keep out most people.

Android

While Android has further options for encrypting data going to and from your phone (such as SSH tunneling), a password is really your best bet here as well. Here are the steps:

• Go into your Android's settings.
• Choose Security.
• Choose Change Unlock Pattern and enter the pattern you want.
• Check Require Pattern.

Other Options

If you want to take it a little further than a password, our mobile security guide can show you how to set up remote wipe and a few other things to better-secure your smartphone. You may also want to set up Find My iPhone for your iDevice (here's how to do it on older devices) or roll your own Find My iPhone equivalent for Android.