What information would you possess that could be deemed confidential related to your eBay business that would concern you?
You are also getting into something deeper than can be properly answered here because you sell internationally so what privacy laws are you concerned with that might (a) govern your business and (b) have an effect on your business.
For the most part, your business is in Canada and its operation is subject to the rules of this country as it pertains to Canadians. Those laws do not necessarily stretch beyond our borders into the US with respect to your US clients or other countries' citizens.
In other words, it would be rare for someone to try to impose the laws of their country on how you conducted your business in Canada with respect to maintaining the privacy of the information they gave you.
The info the CIBC has on clients and released in error clearly violates our laws as it pertains to Canadians.
The US farmer who rec'd the faxes contacted the CIBC several times but they never took corrective and immediate steps to stop the faxing of confidential client documents to the point that the farme lost business as his fax machine and telephone line was tied up for days at a time receiving all these documents.
The bottom line towards confidentiality is this: Your business is NOT charged with receiving and maintaining confidential information. It is not recognized as an institution or part of an industry that would have any responsibility to collect and safeguard confidential information. Therefore, dont worry about it!
Malcolm