Log file that's ideal for piping in to xscreensaver

xscreensaver has a feature where it can incorporate some text into some of the screensavers from a given arbitrary command. It'd be neat to set that to read lines from some relatively interesting logfile.

I obviously don't want my screensaver typing out anything sensitive though. So what log files that can generally be expected to be on a Linux machine have things going on them regularly that aren't super boring stuff like, say, an Apache server logging every GET request, and don't contain any sensitive information? I'm on Debian ruing KDE, if it matters.

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