Compulsive hoarding (or pathological hoarding) is the acquisition of, and failure to use or discard, such a large number of seemingly useless possessions that it causes significant clutter and impairment to basic living activities such as mobility, cooking, cleaning, showering or sleeping. A person who engages in compulsive hoarding is commonly said to be a "pack rat", in reference to that animal's apparent fondness for material objects.

Digital Hoarding

Digital hoarding involves collecting files on ones computer beyond the point of usefulness. Often, files can be acquired through internet piracy at no monetary cost, leading to extraordinarily large collections. Examples include music collections, often in MP3 format, beyond what ones enjoys or can listen to. Other examples include TV shows, movies, and computer games. Hoaders, or digital packrats[6], often resort to buying optical media or new hard drives[7] to store their collections, rather than deleting what they may never use. Digital hoarders find it just as difficult to press delete as traditional hoarders find throwing items in the trashcan, have the same feeling of clutter and chaos, feel that they might find the item useful "someday," and similarly spend large amounts of time acquiring and organizing their collections.[8] Scientific American remarked that humanity's propensity for data collection is growing at a rate faster than their ability to store it.