What are the ways a page can be made public or private?
There does not really seem to be a sense of private posters, however posters don’t really have to be shared, so there is some privacy through obscurity. The ability to set your poster to “public” or “hidden” is in the preferences popup in edit mode.
All pages published with Marquee are public. Edits to pages that have not been published can only be seen by the creator, but there is no public access to pages that have not been published.
It appears that pretty much everything is geared at public access. But so little is available yet that this could be wrong. A structure similar to twitter (heavy tilt to public with a few concessions to privacy, aka direct message) seems likely.
Privacy settings for a flyer can be unlisted, public, or “super” which is described as “optimized to get as many visitors as possible.” This last option presents the reader of your flyer with a more intrusive request to share your flyer via Facebook and Twitter (with more features to come).
The only privacy afforded a tackk is opting out of the Tackkboard.