@juan_carlos: Short answer: indirectly, yes.
Long answer: in and of itself, no, but if you keep them safe in a backup somewhere, and put them back after a factory reset, it'll automagically restore everything on the next boot. So you 'need' them, but in a kind of theoretical fashion, and only in very specific circumstances, circumstances which imply human interaction.
TL;DR: For less than a MB of space occupied, if they're here, assume it's for a good reason, and don't touch them
.