Sorry for getting to this so late. It's called implied consent. A pax has the right to turn out and walk away any time before what Cee stated. You could be in the 5th slot waiting to get your stuff x-rayed, decide you don't want to go through with this and leave if you so choose. As sad as this may sound, once you're belongings are on the belt and/or you step foot into the WTMD you've given up that right.