not true for all customers - I needed to send them nothing of the kind (in the US)
This was dedicated servers (root servers they call them) - and I'm from Europe.
they haven't been doing this forever, so if you've been a customer for a while, you might not have been asked.
they also don't ask business customers (might not be true for all countries) if they supply certain details about their business.
Hey - I didn't have to provide anything but a CC number and I'm based in Europe. We don't have a huge account, how many boxes did you order?
"Since you're a new customer with Hetzner, we ask you for a scan of your passport or ID card (authenticity check). It's only necessary for your first order with us.
Please send the scan by fax or as an email attachment."
When they say they delete it after 21 days, as they did in the mail I've just received, I trust them. I find their communication on this matter, as well as previous matters, open and serious.