+
+ Now here's a thing that sucks about this: if the user actually changes
+ the time of the machine, it will either trigger or delay the triggering
+ of a lock. On most systems, that requires root, but I'll bet at least
+ some GUI configs let non-root do it. Also, NTP attacks.
+
+ On Linux 2.6.39+ systems, there exists clock_gettime(CLOCK_BOOTTIME)
+ which would allow us to detect the "laptop CPU had been halted" state
+ independently of changes in wall-clock time. But of course that's not
+ portable.
+
+ When the wall clock changes, what do Xt timers do, anyway? If I have
+ a timer set for 30 seconds from now, and adjust the wall clock +15 seconds,
+ does the timer fire 30 seconds from now or 15? I actually have no idea.
+ It does not appear to be specified.