I took my 90 year old nearly-blind father to an Aldi discount grocery store in Louisville, Kentucky on Saturday 9/9/06. For those who are not familiar with the chain, this is a discount store that caters to the elderly and others who are on limited incomes. I pushed a cart to my dad and he missed catching it. It rolled about 3 feet into the side of a truck which was parked up on the sidewalk, obstructed the entrance to the store. The ocupant was loading groceries with his wife. The occupant started screaming and threatening my father and asking for immediate money. I did not see any visual damange to the truck as the cart had plastic bumper guards on it. I told the man so and he screamed that he was going to go over and damage my vehicle. By this time customers going into and leaving the store were starting to become afraid. One couple stated 'we're getting out of here'. One lady commented that she was afraid he might have a gun. I suggested to the man that he call the police, then I escorted my elderly parents into the store for safety. We informed the manager of the incident. The man followed us into the store and started demanding information from management about our identities and personal information. We stayed in the store for over 45 minutes and left when we saw the police come, who were called by the man. During this time, there were many comments by customers coming into the store voicing concern that the management was allowing the man to continue to rant and rave outside and voicing concern that the man was harrassing an elderly man. At no time did Aldi's management ask the man to leave, call the police, or attempt to protect or reassure my parents or the other customers. I feel that Aldi's breached its duty to provide a safe environment for its vulnerable frail elderly customers.