I noticed something a little unsettling and wanted to know if it's of any concern or if there is some sort of security feature in place (ie. login timeout) to prevent it.
I found that if a user is logged in when their EOT expires, they will still have access to the site for as long as they remain logged in. As long as they don't clear their cookies or sign out the EOT will never take effect (until they logout).
I know there is a plugin for auto-logout of inactive users but assuming you aren't using something like that, does s2member have anything built-in to prevent this?
http://wordpress.org/extend/plugins/auto-logout/