I've been out of the loop I guess, but apparently it's a Kinja "feature" that if you save a draft in a space that isn't your personal Kinja, then the draft is visible by other Kinja authors in that space.
I mention this because when I discovered this I found myself having access to posts that were clearly written and intentionally witheld from being published to a wider audience. I feel kindof dirty knowing I have this access though I avoided reading anything that was too personal.
Anyway - if you are writing a personal post, or any post that you don't want other authors to see, then save you drafts to your kinja space as a draft rather than to a particular space (i.e. Backtalk, GroupThink, TAY, hackerspace, whatever). If you save it to a space with other authors, they will be able to see your drafts.
Happy Kinjaing and thank you for your time!