I bought a "new" Callaway FT3 Driver last summer from an ebay online store located in Canada (as am I), that had a 99.9% positive rating with thousands of feedbacks, which was supposed to be shipping from Canada. When I received it, it actually had shipped from China (not Canada) and was fake. I might not have noticed (it was pretty authentic looking with a serial number and everything), but the shaft had a very small crack in it, which lead me to suspect a problem, and I discovered it was infact a counterfeit. I went down to my local retailer and carefully looked over one of theirs and noticed that the grip on my fake, while looking the same, had a funny smell and different feel, and also the "plasma weld" around the face and body of the head was just a shiny black metal groove, rather than the duller, coarse plasma weld on the real thing.
I confronted the seller about the fake (and damaged) club, complete with pictures - they claimed that they didn't know, and got it through a distributor. Fortunately, I had paid via PayPal, and the seller didn't want me to file a fraud claim with them and they gave me a full refund.
Since then, I have not purchased any more golf equipment on ebay (well, except a replacement head cover for my 5W).