Requiring IDs like this might actually facilitate ID theft because criminals could create fake host listings and then request all sorts of information like this in order to steal identities. Much easier than breaking into houses to steal them.
It's the roomorama service requesting proof not the users.
Oh I know it is in that service but I don't think that's what the poster I was replying to was suggesting. He's suggesting as a host that you do that (although perhaps I misunderstood).