The danger zobzu referred to was that the pages containing sensitive information might be paged out to disk. If that should happen, you're pretty much out of l

The danger zobzu referred to was that the pages containing sensitive information might be paged out to disk. If that should happen, you're pretty much out of luck: they're just as vulnerable as anything else on disk. The only defense against this is to make sure that the sensitive information is never paged out, using either mlock() or just not having any swap on your system. There's also the class of bug whereby the software starts spitting out stuff from somewhere in memory that was never meant to be displayed, a la the Minus World in Super Mario Bros. Those are much less common in these days of memory protection and high-level languages, but it is still a concern.