Costco Wholesale was also a victim of the PNI Digital Media data breach incident.
PNI is used by several retailers to manage their photo sites and breach attack on it forced many retailers to taken down their sites to investigate or as a precaution.
The investigation confirmed that the breach has affected hundreds of its customers in the area.
Source: https://www.itproportal.com/2015/07/21/costco-now-hit-by-alleged-pni-data-breach/
"id": "COS233225422",
"linkid": "costco-wholesale",
"type": "Breach",
"date": "07/2015",
"severity": "100",
"impact": "6",
"explanation": "Attack threatening the economy of a geographical region"