One place that I worked, years ago, even unplugged the phone after hanging up.
Tell your friend to get an iPad. If he get any Sh-- from the security types he can tell them to check with the White House.
Apple’s iPad invades the White House -
post #24
PS- In a classified area all ports such as USB, serial, etc are blocked. It's been a long time, but I don't think that you have
any access to "your" computer other than to a mouse, keyboard, and monitor that meets the Tempest requirements. That may be different if the material is just classified Confidential.
Military Tempest Requirements