Applications come w ith a risk 'not all application dev elopers have your best interests at heart. Dev elopers have access to a lot of your Facebook information and that of your friends. They may use this information for marketing, or they could use it for something else entirely. From Account > Privacy Settings, there's a link to "edit your settings" for Applications and Websites.
From there, you'll need to access most of the options to change them from the default.
Ensure "Game and Application activ ity" is "Friends only". Then, click on "edit settings" for the "Information accessible through your friends'. Un "check all of the check boxes as shown and sav e.
This w ill stop the applications your friends add from accessing your details. You nev er know who's going to add a dodgy application.
Facebook's 'Instant Personalisation' is not yet enabled worldwide. But, 'edit settings' and deselect the personalisation option if possible. Note that it's checked by default, so as soon as this is av ailable in
your area you'll probably w ant to deselect it ASAP.
"Facebook tips: Managing Applications & Websites"