Stackexchange seems to try very hard to hold on to your identity. In particular, even if you delete all cookies and log out, it still somehow often remembers who you are. If you have multiple people using the same computer and different stackexchange sites it can all get very confused and confusing. Each individual stackexchange site tries to hold on to your identity and will sometimes even overrule the identity which you have just used to log in with.
Is it possible to have a nice clean "switch user id" option which logs you out of all stackexchange sites and gives you the new id you are logging in with?
I understand there may be some risk of abuse but it's not clear to me why it would be any easier to abuse a clean and consistent system then the currently rather confused one.
To clarify, my use case is for multiple people using the same computer (and browser).
However, it is also worth noting that gmail, for example, both provides a "change user" function and also explicitly makes life easier for people you have multiple accounts open on the same browser (see https://support.google.com/mail/answer/1721977?hl=en) . There are perfectly innocent reasons to want to do this.
Slight clarification. Really this feature request just boils down to a "log out" that actually logs you out and doesn't try to remember who you were after that. A "log out from all stackexchange sites" option would be particularly good.