Such hashing does not seem straight-forward to me. If you make it very exact, it's easy to get around. Use another email address, use a prepaid phone card, inse

Such hashing does not seem straight-forward to me. If you make it very exact, it's easy to get around. Use another email address, use a prepaid phone card, insert a middle initial, spell the street address slightly different and the hash will not match. The more fuzzy you make it ("normalizing" the data before calcukating the hash), the more likely it will cause a false positive for legitimate users. It's probably only a matter of time until we read articles on HN where such an algorithm got it wrong.