Shut down my account, blocked my ads and my credit card.
"We are writing to let you know that there has been irregular login activity on your account. We have investigated your account and believe it has been compromised. The next time you log in, you will notice some steps to help you regain control of your account."
I lost a personal Facebook account because of that verification process.
A lot of my friends like to tag people to random / silly things in photos as jokes. But Facebook used a lot of those when I got locked out. Needless to say I couldn't always answer right when shown a picture of a shoe, Homer Simpson, an ad for a Japanese face exerciser or a photo from a concert showing the audience at a festival.
The thing is that for other people it could go the other way. Imagine a small group of friends that only tag real, clear photos of each other. It's entirely possible that an outsider could know each of their names and get into the account easily.