Well here's what I could get till now
Get the uid from each of the usernames >> we get a binary text >> convert it to ASCII and get "47a984720d165e0e10c64288f422a191594390ef"
Now that seems like a SHA-1 or Ripe-md 160 hash maybe? Not sure how to proceed but that's a clue I guess.
So far so good !
Hint #2: that code is SHA1. You have to find out the string that produced that hash by what ever means you see fit and you can give the correct answer
