If you are using Facebook, and who is not really, you are probably aware that what you post publicly on the site is accessible by anyone. That's why you can limit the accessibility of information to certain groups of users, friends only for example or friends of friends, so that information are not just available to anyone who happens to stumble upon your profile.
Things become more complicated when it comes to apps on the social networking site. If you want to run apps, you usually have to allow them to access information about you that they request. This can be your email address, photos you have posted, your friends list or your age and gender.
That's still fairly accessible on the website, as you get a list of all permissions that an application requests on Facebook before it is enabled. In other words, you have to explicitly allow the app before it gets access to the data.
What many Facebook users do not know is that there is another way that part of their personal information may leak to apps, and this time without their doing.
Other user groups may have access to your information. Friends for instance usually have access to most information that you have published on Facebook. If those friends run apps that request information from friends, then your data may leak to apps even if you do not want that to happen.
Facebook has privacy settings for that however that you can modify to make sure that only information that you are comfortable with leak to apps your friends run.
Let me show you how you configure that option.
You need to open the App Settings on Facebook. You can do so either by clicking on the link int he last sentence, or with a click on the small dropdown arrow at the top right of your profile, the selection of settings from the context menu, and the selection of Apps on the page that opens up.
Here you find listed all apps that you are using. You may want to go through the list as well just to make sure that only apps that you are still using are in that list. If you find old apps listed here that you do not use anymore, retract the permissions you gave them and remove them from your profile.
Below that is the "Apps others use" section. Click on the edit button to the right to change the data that apps that others use have access to.
All checked items are accessible by apps that your friends run while all unchecked items are not. If you do not want any of the data to be accessible, uncheck all items and click on the save changes button afterwards.
Note that you do not have control over all profile information here. The only option to block all information from being accessible by apps is to turn off the apps platform. This may have consequences though, as you cannot use apps or games anymore, and also cannot use Facebook to log in on third party sites or services.
If you do not do any of those, you may want to consider turning of Platform apps though.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.