I'm trying to think what the session middleware https://github.com/ring-clojure/ring/blob/1.9.0/ring-core/src/ring/middleware/session.clj would do in a case where two different clients had the same session key. If client A tries to log out and B tries to keep changing the session all the time, would it go possibly like this: 1. request from A gets the session added 2. request from B gets the session added 3. response to A deletes the session from the store 4. response to B re-adds the session, and write-session does not care that it didn't actually exist anymore Or similarly for when the session keys are not the same, but A tries to log out all sessions for the user.