Dear Katrine,
there's a lengthy thread about this issue elsewhere on the forum- the terms of service have contradictions as members aren't allowed to ask one another for identification and the contract for performance (renting a space) explicitly stated to be between host & guest.
I'd ask for id and if you are renting out a remote location where you aren't going to be on site I'd be leery indeed, if your guests trash the place you are on your own in dealing with the aftermath. If you are a host on site I'd ask, in a chatty informal way, what brings the guest to your area (and ask for id) Sally