Oh, I get it. ACS Classic never had this feature; I guess someone else more familiar with OpenACS will tell you if it's a part of the current toolkit, but I haven't seen any comments/talk about such a beast.
It might be rather tricky to figure out how to gracefully deal with people who don't explicitly log out. If a user has a couple of computers, login accounts, etc. how does one determine which user session is the "valid" one? The first? Worse, this scenario sounds rather annoying for the end user.
