Why is it that nearly every app you install on phones and tablets includes sharing features? They frequently pester you to connect your Facebook, Twitter, Google+ and other social networking accounts. Is this a good idea though? You can end up sharing too much with people you don’t know and this can be dangerous in ways you never realised.

Some sharing features in apps are just plain silly. Like those apps that measure your heart rate when you place your finger over the camera lens on the back of the phone. Why on earth would you want to share your heart rate on Facebook, Twitter or some other social network? Who would be interested? Not even your doctor, after all, it is hardly an accurate way of determining the health of your heart.

That sort of sharing isn’t dangerous and it is just pointless. Many apps have pointless sharing facilities that share stuff not even your closest friends would be interested in.

The problem is mostly with health and fitness apps that track your activities. Running, cycling and other apps such as Strava, Runtastic, Runkeeper, Endomondo and others have privacy issues that you need to be aware of.

People typically step outside their home and start the app as they set off for a run or cycle ride. The GPS in the phone is used to track your route, the distance covered, time taken, average pace and so on. When you return home you press the stop button and your activity is recorded. There is even a nice map showing the route you took.

You will be encouraged to share this activity with the social networks you use and the app’s community - most have an online community where you can see other friends and people’s activities, follow people, have people follow you and so on.

That lovely map showing your route pinpoints your home. When you share it, you are telling the whole world where you live. Do you really want people to know your address?

This is a particular problem for cyclists, especially cycling enthusiasts that spend thousands on the latest and greatest top-of-the-range bikes. There have been news reports that thieves are using these activity tracking apps in order to target people with expensive bikes.

Cycling enthusiasts are proud of their expensive high performance carbon fibre road bikes and they post photos of them in their profile or along with their activity. This means that a thief can see that you have an expensive bike and from your route maps they can see where you live. All they need to do is to wait until you go to work and then break in and take your bike. Security is often poor and bikes are kept in garages or sheds, which makes the task easy for the thief.

What can you do?

It depends on whether you want to continue sharing your activities or not. You could turn off all the sharing features in the app and ignore any prompts to share an activity when you have completed it.

Sharing features are not just in apps themselves and if the activity tracking app includes an online community you should log in to the website using a web browser and check the privacy settings on your account. Log in to Runtastic (runtastic.com) for example, click the arrow next to your name in the top right corner and select Settings. Click Privacy on the left. There are eight privacy options and you could turn them all off, or just selected ones like Maps of activities.

Some people like to share their activities and for those, the solution is to start and finish recording some distance from your home. It does not have to be far away and if there are a lot of houses around you, then simply walking for one minute in any direction is far enough so that no one can tell which house from the dozens around you that you live in.

You just have to judge for yourself how far to go. Just make sure you don’t start recording an activity right outside your door.