I don't have any problems with privacy but when I finish a journal (usually takes a couple years) I read through it again and take notes in the first few pages of my new journal and then destroy the old one. Three quarters of my ramblings are just complaints or mundane stuff that I don't need to keep. I just find the ideas I still like or note dates I started something I'm still working on, etc.

When I wasn't keeping a paper journal but was online 75% of my time because I was going to school, I kept a large, blank, "sketch" book next to me so I could take notes/find my place, etc. when I was working online. It had passwords and hotel reservations, etc., LOL in addition to ideas for papers and what I was thinking and lists. Became a sort of journal, the best sort I love with drawings and words every which way. I didn't worry about that being read or bothered since it was such a mishmash and not very interesting to anyone but me.