These are John and Jane Doe. The 2nd and 3rd ever roblox accounts. Although they were hacked and now the hacker owns those accounts, They were NPC-like accounts that would join empty servers with people, like if someone joined an empty server, John and Jane Doe would hop in there with them, and would even chat and play with them. If you get a weird message from John Doe, That means he's coming for you and that you're next to be hacked. It is actually pretty dangerous if you get hacked by John Doe. Reason why? HE CAN GIVE YOU A VIRUS.
Credit to all, and John and Jane Doe.
