Hashes of phone numbers is unfortunately not actually useful in almost any circumstance. You can trivially reverse them by iterating through every phone number and computing the hash.
Hashes of emails is not quite as useless, but not far off (consider 90+% of emails are at like ~3 domains, and also that lists of vaguely ~valid email addresses aren't hard to get).
Hashes of emails is not quite as useless, but not far off (consider 90+% of emails are at like ~3 domains, and also that lists of vaguely ~valid email addresses aren't hard to get).