Whether or not David Schlesinger approves of the FSFs action or that companies like 'best buy' are considere distributors:
The legal situation is quite clear. Even if you are a retail store that is selling some products containing software (either on CD/DVD, or on flash memory inside an embedded product): You are bound by copyright law and you need to make sure you have the right to distribute those copies.
If that is practical or not, it is an existing legal situation. And it is in many cases the only way how to ensure GPL compliance at all, e.g. if those retailers buy directly from a foreign vendor, or they buy from a source that is unknown - the only lead is to go after such distributors.
The claims you may have against them might be different than against the original infringer (if there is such an entity), but still you can ask them to stop their behavior in violation of copyright.