For everyone buying hosting services, I need to know some personal information about you. Specifically I need your real name and valid contact information, such as: e-mail, online name & "universe" (for VR hosting customers), street address, and phone number. This could be a work address and phone number, PO box, or other address/phone information, but under normal circumstances I need to be able to reach you within a few days.
If you are buying hosting services for someone else, I need the full contact data for the person responsible for the content being hosted. I also need to at least have valid e-mail addresses for the other parties in the transaction, i.e. the purchaser.
I need this information should I need to get in touch with you for any reason. For example, to notify you of expected changes in my network, new services (included free or otherwise), planned outages (in advance), unplanned outages (after the fact), etc.
This is personal and private information. I will not sell or rent this information to any other person or group. However, if presented with a court order to divulge this information, I will.
Protect yourself: If I assign additional FTP accounts or email accounts to you, so that you can let others use these accounts, I suggest you keep at least some "real-world" contact data on your people. You are responsible for their actions on my network. I can discover a surprising amount of information from log files and ISP logon data, but a real name and email address can be useful.