I don't know why they would use a centralized service with servers located in France.
They could have used a decentralized service like Jabber encrypted with OTR and configured to not store messages.
The smart thing is don't use PGP at all. Criminals are lazy I guess, oldschool mafiabosses like Provenzano had a pizzini system much safer but it takes time to communicate in particular when you want to send a message to the other side of the world.
Ennetcom, MPC, IronChat and PGPSafe have already been dismantled by the police. At the moment, Sky's service is still very popular in the criminal environment, as it is known that it has not been cracked by the police.
