From what I remember poking around at Hansa that's not true. Each vendor / user had a public key associated with their account. All text communication through the website was supposed to be with GPG encrypted text secured by private keys unavailable to website.
So law enforcement has lots of encrypted text along with some clear text from users not informed enough to follow any kind of opsec.
So law enforcement has lots of encrypted text along with some clear text from users not informed enough to follow any kind of opsec.