Recently I got Stuck on The same problem , I have Logged from Windows 7 and Then i Upgraded my Windows to Windows 8 and Logged in To Facebook again . Then after a day later i Got This Message -
Someone May Have Logged In To Your Account
In Order to keep your information secure, we've locked your account. Before we can unlock it, please verify your identity and change your password.
Your account will remain hidden until you complete this process .
Now here is a Quick Solution of this problem -
After that you will press Continue and Will be redirected to a new page and will see this -
Please Confirm Your Identity
To Confirm your identity , please log in from one of these browsers you have used before:
Chrome for Windows 7 (10 july at 21:50 )Alternatively you can upload a photo ID to confirm your identity
If you have not then Just Log in from the Browsers Give in the Page - Please Confirm Your Identity .
Solution 2 - ( Worked for me :D ) You will see an another link Upload a photo ID . Click on that link and Just upload any one -
3.Any government Card
The cards must show your Proper name , Birth date and your Photo . You can click Photo with any Camera or Scan it and upload it .
If you Don't have Above ID's or Card's just Upload the two of them -
1. School / College Id card
2. Library Id card
Which must show your Proper name , Birth date and your Photo . You can click Photo with any Camera or Scan it and upload it .
Then complete The process by giving your id etc ..
And Just wait and Sit back and Just Wait for A Mail from Facebook it can take upto 2-3 days . I got my mail in 1 day . Don't loose hope , because u will definately get back your account , your pages and all your contacts , Don't make a new account in same name again .
Note - Keep mailing Facebook your id's and u will get back it definitely , also
Note - Don't try from log in from different computers , browsers as that will not help you anymore from getting out from the problem .
Feel free to comment if your find any problem !