Please don't read this as a defense of Matt Stock. I agree with almost all objections to his "new artist" sketches that have been voiced here.
However, if we're going to object to use of "copyrighted characters," then where was all the outrage when Jay Lynch was producing such sketches for years without any Topps affiliation?
For me, the whole thing hinges on the intent of the person who is creating the "unofficial" cards. In Jay's case, he's a seasoned artist with a long legacy of work on real Wackys with Topps who is just trying to pay a few bills with some extra-cirricular work. I know that Topps doesn't pay their artists particularly well, so I certainly don't blame Jay for wanting to play in the sketch market. And everything he's sold has been spectacular in terms of quality, so at least you're getting something good for your money.
These "new artist" OS3 cards on the other hand appear to have been made with the sole intent of extracting money from unwitting collectors. If you want to get really cynical, you could even argue that they're meant to undermine the whole "Old School" effort by flooding ebay with a bunch of fake crap that will ultimately drive down the value and collectibility of the real sketch cards. The "altered" cards that have been offered up by this same seller will almost certainly have that effect, as it will become nearly impossible over time to distinguish real cards from cards with added color/details. What I don't understand is why Topps seems to be sitting on the sidelines and doing nothing to stop it. It's their brand - don't they care?