House Raided By Wal-Mart Loss Prevention?!?!?

Where the hell does Walmart get authority to conduct a search of a private residence? Am I missing somthing in the article here or have corporations truely taken over?

SNIP:
A Team of Wal-Mart Loss Prevention Agents, up to 5 or more, stormed into a resident’s home and conducted a search warrant. Parents allege that item(s) were stolen from their home during the search. A complaint was filed and more were in the process of being filed until the family and child began to receive numerous threats which were racial towards the child, sexual, homosexual and threats with the intent to do bodily harm