There are almost 500,000 applications that are available in Facebook. According to new policy of data storage Facebook applications like Farm ville etc can access your personal data which you update in your facebook account. We can’t say or even facebook team can’t say how can app developers can use data which is collected which seems to be risk for us. As a end user, we can minimize the risk by removing the unwanted apps in your facebook account. This will not only minimizes the risk but also stops unwanted notifications that are coming from those applications.
Let us see how to remove facebook apps in details
Go to Account -> Privacy Settings in top right corner of your profile page
In Privacy settings in bottom of page Click Edit your settings under Apps and Websites as shown in below figure
It provides a page which give list of apps you are using, click on remove as shown in the below figure.
Click Remove to remove the respective application.
Thats it. Let me know if you face any problems.