I was sent a shipment recently and the sender didn't put my last name. So the courier asked me to email them a copy of my passport or driver's licence. I rang them directly and was told that this is the only way of providing my identity. I said hell no and the package was sent back (they ended up resending it with my full name).
I find the worst culprit to be healthcare providers. I've had two recently ask me to send my credit card information in the regular mail. I drove down to one of them to do it in person, and they put my details in a filing cabinet. I sure hope that lock is good!
(Pro tip: if you ever need to send CC details via mail and you cannot arrange an alternative, use registered post with signature so you can confirm it made it to the recipient)