Thomas Aquinas wrote, "Greed is a sin against God, just as all mortal sins, in as much as man condemns things eternal for the sake of temporal things." In Dante's Purgatory, the penitents are bound and laid face down on the ground for having concentrated excessively on earthly thoughts." - Wikipedia: Seven deadly sins/Greed
"Hoarding of materials or objects, theft and robbery, especially by means of violence, trickery, or manipulation of authority are all actions that may be inspired by greed. Such misdeeds can include simony, where one attempts to purchase or sell sacraments, including Holy Orders and, therefore, positions of authority in the Church hierarchy." - Wikipedia: Seven deadly sins/Greed
They want to own everything that you will ever need.