Content that exists only on one hard drive is stored temporarily, but nowhere near forever. So while it may be true that we have the technical capability to hold all of human knowledge in our future nanoflop crystals, we never will.
Content outruns storage because humans store things capriciously and illogically. Plus, we never make backups until it's too late.
Annalee Newitz is a surly media nerd who almost lost this column because she forgot to save it until she was nearly done.