Contacthackerpro001 @ GMAIL COM massively oversimplified for anyone wondering what are private keys. There are two components to your ownership address: a public key and a private key. Think of the public key as the username on a forum like this. Everyone can see your activity but no one can access the account. The private key is like the password - once you have that you can control everything in the account - make posts, delete the account, etc. The Feds basically found this person's private keys (password) stored online somewhere and used it to log into their Bitcoin wallet and liquidate the funds. I am massively oversimplifying here, but hopefully that helps.