I read somewhere that the no-fly list is so widely distributed that currently known terrorists are not actually placed on that list as this would leak informati

I read somewhere that the no-fly list is so widely distributed that currently known terrorists are not actually placed on that list as this would leak information about who the US considers a terrorist to too wide an audience. Obviously I have no way to validate that story, but if true it would cement the story about that list being an utterly useless farce.