How is this a violation of personal privacy? Sending mail? Submitting name & address to a business, a readily available datapoint for probably anybody?
When people share their address with businesses, they are generally protected under laws like GDPR and CCPA.
OP’s site seems a bit hosed at the moment so I can’t dig into their privacy policy and see how they handle GDPR and CCPA deletion requests.
Only in the EU or California.
I am no lawyer. Before collecting data, better talk to one.