There are a variety of reasons as to why they do this and as long as you know why, in most situations, the way to solve it is comparatively simple, albeit annoying.
You may have attempted to access Facebook account one morning, and been faced with a message that your account had been disabled, or locked for protection reasons. This would absolutely come as a shock and without any purpose given you will feel hopeless.Factors why you’re Facebook Page May Have Been Locked
Fake Account: If you didn’t use your actual name Facebook will gradually find out.
Misunderstanding: If you created a page that impersonates an individual or entity it will be locked or even closed without alert.
Groups Joined: You have joined a lot of groups. The maximum limit is 200 groups per user.
Spam: If you published too many messages on a wall or in a group in a too short time span, it can be considered spam.
Friends: You may have friend-requested too many individuals. Facebook has instituted a maximum 5000 friend’s policy so this reason should be a rarity.
Under Age: You are under 18 years old and not part of a High School group.
Bad Content: You wrote offensive content.
Hacked: Someone may have tried to gain access to your account so Facebook needs you to verify you are who you say you are.