Based on the search results, particularly the privacy policy of the "BAND" app:
Collection of Phone Numbers: The "BAND" app does collect phone numbers in certain situations:
When a user signs up with or links their LINE account (in this case, the phone number subscribed to LINE might be collected).
When selectively gathered for the use of various features specialized for the service (this implies phone numbers of individual acquaintances invited by members or registered as impacts of overseas chinese consumers in uk members before joining might be collected).
For any inquiries about the service, the login account (which could be a phone number subscribed to BAND) is collected without exception, and the (mobile) phone number will be selectively collected.
In the event of reporting infringement upon rights, a mobile phone number might be collected.
Use of Phone Numbers: The collected phone numbers are used for:
Connecting to the account via connecting means (like LINE).
Identifying the user within the service.
Inviting friends to BAND (the phone number might be exposed to the invitee if selected as the invitation means via SMS).
Inquiries about the service.
No Indication of Public Database: There is no indication in the provided search results that "BAND" (the app) makes a database of user phone numbers publicly available. The focus of their privacy policy is on the collection and use within the service and for specific features.
Therefore, it is highly unlikely that a publicly accessible database of "BAND" app user phone numbers exists. Obtaining such data would likely involve violating the app's terms of service and privacy policies, as well as relevant data protection laws.