On Linux systems, most system-relevant processes keep logfiles that record what the software has been doing. Although this feature is fantastic for forensics experts and system analysts, users normally hate it. The verbosity of the various daemons and applications leads to continuous growth of logfiles that are not actually needed on a working system in normal circumstances. At the same time, some services also create rotating archives and backup copies of the logs, thus consuming even more disk space.

But that's not all: Among the ranks of these relics, which I am sure are saved with the user's best interests in mind, you will also find the cache files that many applications use to improve hard disk access speed. Web browsers are the major culprits here; besides storing a history of the websites a user visits, they also include content such as images and graphics to provide a faster load time the next time the user visits a page. Firefox and other browsers also save website cookies by default.

Even multimedia applications like Rhythmbox, the proprietary RealPlayer, and most Chat programs hoard tons of user data, causing even computers with a minimum of usage to build up considerable data collections in the course of time. Apart from the fact that these files waste a lot of space, keeping a detailed record of your usage is quite dangerous for your privacy: the files, many of them in clear text, reveal a comprehensive record of the user's behavior.

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