This sounds like a Travel Safety & Security thread if that.

Convicted sex offenders should be in prison serving their sentences, so putting them on a blacklist is basically useless.

Once a convicted sex offender has served their sentence and are released from prison, if ever, they are generally free to fly. A good number do end up on various blacklists, effective or not as those blacklists are.

What does "sleep" have to do with this? Would a rapist much care if someone is sleeping or not? A serial rapist is not necessarily going to be dissuaded from raping someone just because a victim-to-be is awake.