[perching_aix]

If I read it correctly it's because they think phones are a no-go from the outset, so clearly apps for those phones are out, too:

> When government and military officials want to discuss operations, they’re typically required to go into a SCIF (Sensitive Compartmented Information Facility), which ensures:

>

> - That they are not being wiretapped. (To this end, mobile phones are not permitted in a SCIF.)

Whether this is actually true or not I wouldn't know and can't be arsed to research, but it makes sense to me. Whether it's reasonable to assume based on this that phones are completely out I also don't know.