1 Lock code: numbers instead of patterns

Tablets and smartphones can be secured with a lock code. It is important to choose a combination of numbers rather than a pattern. The wipe marks of the pattern can be seen on the touchpad if you hold the device up to the light.

2 Do not share your location

Apps such as Facebook Messenger want to access your location. Where you are, however, is nobody's business unless you are using a navigation app. You can switch off or restrict location services for other applications in your smartphone settings.

3 Surf securely with encryption

Make sure that the address line of the browser contains "https" instead of "http". Data is then transmitted between the website and the user in encrypted form.

4 Be careful with online games

Social networks are teeming with free, entertaining online games such as "Farmville", and more and more free game apps are coming onto the market. The crux of the matter: in most cases, you not only release a lot of personal data when you install the app, but later also unknowingly when you play - and often also that of your friends.

5 Using Google search without logging in

Do you see a blue box with the word "Sign in" at the top right when you use Google? Great - that means you're not logged in with your Google account and the online giant can't access as much of your data. If you are logged in, you'd better log out. The Google Search, Google Maps and YouTube functions also work this way.

6 Skepticism is simply always appropriate

Whether it's cat pictures, supposed bargains or competitions: Be skeptical of free offers. They often just tap into your data on the internet. The rule is: "If you don't have to pay anything, you are the product!

7 Deactivate cookies

Cookies store data on a website. This is convenient because users do not have to re-enter everything every time they visit. The downside: they are often used by companies that use them to record your surfing behavior. Therefore: Block "third-party cookies" in the settings of your browser, such as Firefox.

8 Disguise sensitive data

Do you want to send private information by email? Make it unreadable at www.privacy-captcha.com. The text is no longer machine-readable and cannot be processed automatically.

9 Log out of Facebook when you leave

If you have not logged out of Facebook and then switch websites, the service is still active in the background and can log your other online activities particularly well. Therefore:always log out properly!

10 Don't respond to everything indiscriminately

"Like" is a thing of the past. With the new "Reactions", you can express your feelings about a Facebook post in more detail. Nice! But it also means that the network can analyze its users even more precisely and place more targeted advertising.

11 Use multiple email addresses

Stiftung Warentest advises not to use just one Internet service, but to use different e-mail addresses for different services and stores. This makes it more difficult to create a comprehensive user profile of you.

12 Find out more

Klicksafe offers explanatory films and brochures on security settings: www.klicksafe.de