If you link to a separate private blog, where you invite only users you choose, then it is still possible on shared or public computers for others to access that information unless the users are scrupulous about logging out of their accounts each and every time. WordPress does have some (long) time limits which save login information and it is unlikely to change that: if one could be logged in for only an hour imagine the difficulty of making a post if one had to constantly keep logging in…

But the real problem is actually with browser cache. If someone uses a public computer, or shares a laptop, then forgets to clear the cache and cookies, the password is saved by the browser itself.

The other issue is that people might well reblog or share passwords with others, further complicating the issue with the browser cache keeping the password protected post possible to access by others.

We have a couple of pages on our site that are intended to be accessible only to club members via a password (see pages under the heading 'Informatie voor leden'). The password protection works fine except for one thing - once you've signed in, you stay signed in for a long time (days), instead of being signed out when you leave the site. It would be really great if we could configure the time-out period, or give the members the possibility of logging out for themselves. However, I've looked everywhere and can't find anything that says how to do this. All I could find was some advice that seems to apply only to wordpress.org sites:
http://wordpress.org/support/topic/password-protecting-pages-how-does-it-work
http://wordpress.org/support/topic/how-to-require-logout-from-password-protected-page?replies=6

Is there anything I can do to either make it possible to log out from the protected pages, or change the time-out down to hours instead of days? Any advice much appreciated!

Thanks,
Camilla