You might have noticed that there are a lot of applications in facebook where you might get tagged by your friends. If you want to disable photo tagging in facebook follow the step given :
# Log in with your Facebook account. In the navigation bar look for
Settings > Privacy Settings and the click on "Profile Information".
# Change the setting Photos and Videos with me, click on the dropdown menu, then click "Customize"
# And then save your preferences as "Only me".
This way your friends can not tag you in pictures and videos published on Facebook.
Also Read : How to Convert, Download Videos off Facebook