Hello,
 
I know that the "green snail" (P. pulcherissima) is on the CITES list due
to the fact that local people were cutting trees down to collect these
snails to sell to tourists. This happened on a pretty large scale and was a
real threath to preserve the rainforest. So it's not only the snail which
was endangered, but an entire environment (habitat).
 
Regards,
Wilco