definitely an issue that received a good bit of media attention a couple years back - they were extremely popular for awhile (and mortality rates were high re shipping inexperience and shop keeping inexperience)Not sure about them being endangered
Personally, until we see successful captive breeding we should stand strong and not purchase these. They will be driven to extinction, and for what?
Tried them about 10 years ago or so, they did not last very long, I would not try them again! There are more common aquatic crabs you can try that are easier to keep! Maidenhead Aquatics usually keep them!
So they have been around for a while then. Surprising how after so long there not commonly bred but by the sounds of it there must be a lot of difficulty breeding them.