There was a recent thread about a news story discussing counterfeit fitness items being sold that looked legitimate and one of the them was P90x. The 'expert' in the news story said the easiest way to avoid buying counterfeit items is to not purchase them from vendors & sites who are not authorized retailers. Ebay, Amazon, Craigslist & Costco are not authorized BB retailers, even for Coaches.
I'm very sorry that some legitimate home fitness users who wanted to sell their unwanted BB dvds were hassled for posting them on ebay, but given how many pirated copies are sold on ebay, I'm not sure how BB can tell the difference between a legitimate re-seller and a bootleg seller.
IMO, ebay can do a much better job screening for bootlegs. Descriptions of workout programs as the "overseas version" would be a big red flag to ebay, don't you think? Even their "feedback" system is not that reliable.