[nickpsecurity]

The policy of most domestic TLA's is to watch for encrypted calls. Those targeting journalists will likely have the journalist's main number in their system. Disposable, dumb phones on both sides are safer. Although the NSA can detect that, I havent heard that many others do or easily.

Typical advice applies, too. Keep batteries out. Drive away from normal location to somewhere with plenty of people in cell radius but off camera. Batteries in, make call. Prearranged times or periods.

[Canada]

Who could possibly do their job like that?

[nickpsecurity]

Lots of executives and lay people that value privacy. I've met many. In this scenario, the journalist really just needs to be able to receive the call. The need for the OPSEC is mostly on the person leaking stories. They can do less if they don't mind consequences, though.