Actually, the important point is more about how much data Facebook can obtain whenever someone writes an app using their advertising revenue SDK, but I'm sure that headline will get more hits ...
Then they know more then I do! 🙂
Seriously, anyone that downloads an app should automatically think to themselves "what of my information will be shared, with whom and how?" and specifically focus that line of reasoning with FB in mind.
And notice I didn't say "IF".
Companies are in business to make money and AD revenue is a sure fire way to get that revenue because they have a treasure trove of information-your data-to sell!