is it really awful? first of all, most probably what people here said, f.a.k.e. second, these particular rhinos, even if it's real, are already dead long ago. and third, if not for bitcoins, they would have been traded for cash (with more precautions but still).
so I say not awful, we should be prepared, being proponents of pseudo-anonymous internet cash, to witness much worse cases of it being used for illegal activity. much much worse than some dead rhino parts.
I don't think it's safe to just assume it's fake. And rhino horn is more often taken from living rhinos by killing them than just rhino corpses, so someone trading these should feel obliged to provide solid proof he is not connected to such things.
With an approach of "wrong, but not so bad", things become muddy very quickly. A line has to be drawn somewhere. I personally like the approach to draw such a line very clearly, tolerate everything up to it and rigorously fight anything behind it. People deal drugs on a simple open market? Whatever. Employ poor children in their factory? Sounds bad, but I don't know whether they'd be off worse otherwise. But people who break into a national park to kill the beings in it for profit? Those should be stopped, by whatever means necessary. I would recommend a method that ascertains the "loot" is destroyed, so that nobody wins in this game. A drone strike on their vehicles would fulfill these criteria; short-term confinement would not, unless one is certain to catch the offenders in virtually all cases. (The profit margin is just too large. People would continue doing it even with the risk of a little prison time.)
Admittedly, someone "just" trading is not technically proven to be involved. It
could be horn from a rhino that died of natural causes or whatever, even if that's very unlikely. I'd still avoid such people -- and anyone who deals with them -- like the plague, and demand more information on WTF is going on.