> In countries where you do have e.g. tax numbers associated with addresses no government agency is going to give it to a random private company.
Why not? In my country the company registry is public, anyone can pay a small fee to get an official certificate of a company's address and company number.
We're talking about different things, what you're describing is the opposite problem. The vast majority of the customers are people, not companies, and no information will be released about them.
The post we're discussing is about a company, so I think that's the relevant case. (And for what it's worth the registry I'm talking about also applies to sole proprietors, at least those who've registered for the associated tax treatment).