I have GNOME's random screensaver feature enabled, and was switched to the
console while X was running random screensavers.  The system became very
slow while typing and my typing just plain stopped.  I switched to a
running copy
of "top" and saw that X was consuming 72Mb of RAM which is eons more than
it usually does.  I have a swap daemon set up which adds more swap
dynamically
in the event of OOM condition nearing.  The daemon had added an extra 32Mb
swap file.  I checked running processes and saw the xscreensaver was
running
out of control.  The screensaver in question is the "teevee" one which
simulates
a television with the vertical hold off kilter and the screen wrapping
around, plus
interference fuzz, and similar.  While it is a cute screensaver, it would
have OOM'd
my machine had I not been cautious and running swapd.  ;o)

This may be exploitable I suppose.. I haven't looked into it though.