Hi Inna22,
I have hosted since 2013 and always have Airbnb do the asking for ID. I live in Long Beach, California and when I stayed in Scottsdale earlier in the month, I was asked to upload my DL or passport into the app by the Arizonan Airbnb host.
I think this is a good idea and may implement on my end. It depends on the conversation I have had with the guest. It is a great safeguard, but it is also a big sign of no trust in the vetting that Airbnb has already done.
That being said, I did have a young guest who tried to change his identity and when I called him on it, he never checked in. But shouldn't Airbnb provide that to the host upfront? It would be great if you could click on a booker's profile, see their ID, and any reviews. ID should be a requirement for any booker - instant or otherwise.