Usually when my PC is on and my browser is on I am always logged into ServerFault, and I don't care much about that, since it is at my home PC.

However, I've been into a friends house yesterday and logged into ServerFault from his PC, but then I've noticed that I can't log out?!

I am using my GMail acc. to log in here, and I tried to log out from GMail, but that didn't help either.

There is no LogOut button, and the only thing that loged me out was the deletion of the browser cookies.

Why there is no logout button on all of stack exchange sites?

Usually when my PC is on and my browser is on I am always logged into ServerFault, and I don't care much about that, since it is at my home PC.

However, I've been into a friend house yesterday and logged into ServerFault from his PC, but then I've noticed that I can't log out?!

I am using my GMail acc. to log in here, and I tried to log out from GMail, but that didn't help either.

There is no LogOut button, and the only thing that loged me out was the deletion of the browser cookies.

Why there is no logout button on all of stack exchange sites?