Cuz sometimes when you are testing things that require you to logout of the forum 20 times in five minutes it would be nice if we could still stay logged into the ACP to make changes without having to re login 20 times in that same five minutes.. For example i sometimes have to log out of the forum as an admin and log into a test account with different permissions to test the changes ive made on a per usergroup basis.. It sucks that every time you go back to the acp to make another adjustment you have to re login.. Im a Joomla junkie and its just something i prefer and am used to on that system.. I know vB handled ACP logins the same way XF does.. Its not a show stopper but its just a preference. Especially right now when im having so many troubles with permissions.. Its driving me nuts to have to re login to the ACP every 30 seconds. Im sure there is some kind of security concerns i just dont know about.. (remember i dont code so understanding how security works in these sessions is foreign to me.) anyways the way the system works that would make a good 40 logins between accounts going back and forth in that 5 minutes from my example.