This would have been so simple to just make right in the beginning. They should have just hashed each of those user names and put the hash into a dictionary. Wh

This would have been so simple to just make right in the beginning. They should have just hashed each of those user names and put the hash into a dictionary. Whenever someone entered an email check if it is in the dictionary. O(1) time and it wouldn't be a "data leak vulnerability". So close...