Same issue as I'm currently having with Airbnb. Though I have never ever provided any ID before, nor did I ever book anything, they asked me for an ID to prove my identity upon requesting account removal. How exactly does my ID _prove_ anything in my case (apart from the fact that I have an ID copy of a person who has the same name as I entered into the Airbnb profile page). Seems more like one more obstacle to prevent people from deleting their account.