well, the only con i can think of, and it's pretty big, is that no matter how noble your intentions are in saving endangered species is, it doesn't justify the means you go about doing it. Saving endangered species is a perfect modern example of the ends justify the means. the most unconstitutional law we have in the books is the endangered species act. it trumps everything. private property rights, human rights, freedom and liberty of american citizens, progress, economic growth all stunted. it can stop any project in it's path, halt economic progress, etc. it's a law with noble intentions that has gone way too far. also, another negative is that once an animal is declared "endangered" it's almost impossible to remove it from the list, no matter how well the species is doing. look at the grizzly for instance, even though it's no longer endangered, it's still on the list, and it's becoming a hazard to some local residents, but if you shoot it, even to protect yourself, watch out! you'll be the one in jail.
1. legislators, environmental activists take advantage of peoples good will in enacting unconstitutional laws to protect endangered species. the ends never justify the means.
2. once a species is declared endangered, it is nigh to impossible to remove it from the list, no matter how well the species is doing. look up all the resistance when an animal is being considered taken off the list. And liberty and protection of human life and property and livelihood be damned!