having a reef tank is can be environmentally friendly with the right considerations for the creatures your keeping. and really, these reporters need to do their homework, it's the curio trade and the fact that they use the limestone from the reef to make roads, foundations and buildings in these countries that is causing the damage, not the legal harvesting of corals for the aquarium trade that is threatening the reefs(granted this was "illegal" harvesting).
furthermore, in 50 years or so, when the rate of coral death in the oceans has really started to exponentially increase, the reefs will be dependant on the heartier, healthier species propagated in captivity originally by hobbyist to reseed the natural reefs.
coral specimen propagated in captivity for say 10 generations are vastly stronger than their wild counterparts, because the captive specimen has only known immitation seawater with levels of salinity and temperature and ionic balance that are in constant flux compared to the ocean. so the change in salinity and temperature that might have killed the original wild colonies will be tolerated by the propagated specimens put under the same conditions.
so, in short, i'd say that when reefs are designed with a "green" motivation of using the least amount of energy with water pumps, skimmers, and lighting, and the needs of the creatures are truely considered, you reef can be very evironmentally friendly... just dont dump your caulerpa in the bay.