I wonder if this is true, or simply hyperbole. I'm extremely curios on the technical details of this bust.
Edit: It appears that some info can be found here https://www.justice.gov/opa/press-release/file/982821/downlo.... Look at the section "Alexandre Cazes: Alphabay's Founder and Operator"
It looks like the founder was extremely careless. His personal hotmail email was included in the header of the welcome email and password reset emails to Alphabay users. He used the same username on Alphabay on at least one forum before creating Alphabay. This username was tied with his personal email and name.