Wpa Kill 2.1.7
Enter the maximum number of concurrent page events that Oracle Application Express supports for each session for applications in this instance. You can configure a specific value at the workspace-level. Instead of processing a new page event, Oracle Application Express shows an error message when the limit is already reached. Alternatively, you can use the Concurrent Session Requests Kill Timeout attribute to kill an active database session, to process the new page event.
Wpa Kill 2.1.7
If a new page event comes in that is outside the limits of Maximum Concurrent Session Requests, Oracle Application Express can execute alter system kill session on the oldest active database session which processes another page event for this Application Express session. The Concurrent Session Requests Kill Timeout attribute specifies the number of seconds a database process has to be active, before it can be killed. If you leave this attribute empty, Application Express will not kill any database sessions.
From a white hat's perspective, or just someone wanting to protect themselves from data theft by black hats or law enforcement, a dead man's switch is most useful for locking things down. Let's say you're in a protest with the possibility of getting arrested. You could set a kill switch for your laptop in case you don't check in via Twitter every so often. That way, it's harder for anyone to access your data.