Facebook is the largest social media platform in the world and it has more than two billion active users. If you have an account on facebook, you may have noticed that your account has been blocked locked facebook problem at some point. There are several reasons for the locked facebook account.
1. Facebook’s clear out process
2. You are performing illegal activities on facebook
3. Avoid facebook warning
4. Suspicious activity by someone on your account
5. Adding massive number of friends

Source – https://www.waybinary.com/fix-temporarily-locked-facebook-account/