There is concern that these beautiful little fish could achieve commercial value, in which case some of them would get wiped out completely. Look what commercial fish collecting did to some of the pretty salt water fish in the Keys, all but gone now.
The vendors that post here are very responsible and only sell legally collected species that are fairly common. Not everyone has these good principles, though, and not everyone will be so discriminating with the endangered and special concern species. With places like aquabid, anyone can go into business and empty a stream. These forums are open to public view, and Google does pick up on the contents quickly, text and photos.
I am actually hoping people start captive breeding these fish to sell and getting good enough stocks that by the time their popularity catches on the market is all but established with captive bred ones. That should keep illegal collecting down, especially if captive breeders press for regulation on sales (sort of like how selling wild caught birds is illegal but captive bred is ok).