Put another way: Intelligence agencies use encryption to protect their secret information, which often times does not include the location of where they are operating. They use SCIFs to protect from attackers semi-remotely stealing their encrypted secrets while they are in a plaintext format (ie: displayed on a monitor). We use encryption to protect our secret information, which almost exclusively consists of the shipping addresses to which drugs are sent. We don't have as much to worry about TEMPEST attacks, because by the time the attacker is semi-remote to our location, they have already identified us and therefor already know our primary secret. Vendors also use encryption in the form of FDE to hide their SR activity, but it will not protect them a whole lot if they are busted with a bunch of drugs anyway. We use encryption primarily to aide in our anonymity, and TEMPEST attacks only work against targets that have been identified.