I bought some knock offs awhile back. Should of known, the price was to good. At least the price I paid was reasonable for a knock off. I resold some of them. I just made sure I told people they were not getting photons and I tossed the packages with the micro photon label. They don't work as will as photons, the cases are stiff and I had to dink around with them to get some of them to work.
I don't mind seeing the copies as long as the sellers are willing to sell them as what they are.
The one tip off I have noticed is if they show the package, make sure it matches the real thing. The knock offs seem to favor the two piece vacu-formed clear plastic shells like in the Ebay pic.