A paper-only journal would defend against the state, but not against people you live with. A digital journal can be encrypted, but an intelligence agency could potentially gain access (like, them reading your anti-government rants that may involve violence… that sort of stuff).
So… how to defend against both threats?
(Also, I just realized, paper journals cannot really be easily backed up…)
Could even put it on a USB drive, so killing it is as simple as yanking the USB. Hell, if the feds come sniffing, you could just toss that bitch in the microwave.