As stated previously, Facebook takes measures to secure your account and others. While Facebook might lock your account to protect it if you’ve been hacked or have suspicious logins, the company will ban users who violate the terms of service. The former means you’ve had suspicious activity, and it is possible to unlock your account. The latter means you’ve posted or communicated something the company deems harmful to other users, and, therefore, may not permit the option to get your account back.