I get a message like this:

Your account is temporarily locked.

It looks like someone else may have accessed your account, so we’ve temporarily locked it to keep it safe. For your privacy, others cannot see your account while it is locked. To unlock your account, you may need to pass a security check.

Note that attempting to access someone else’s account is a violation of Facebook’s terms. It may also be illegal. If you are not, press Cancel. [italics mine]

If I am not what?