Privacy of Customer Information

However there are some companies that feel that their customer
data is confidential, and refuse to reveal it. (Also if they
use rwhois fixing swip won't solve the problem completely.)

If you want to give your lawyer a heart attack, ask her if the
data is covered under Title 47 Section 222 Privacy of Customer

Have you noticed the companies that are most likely to refuse
to register their customer data, are also the the ones most
likely to have a large direct sales organizations which uses
such customer network information for its own marketing efforts.