My doctrine would be appropriate in this case.
Do unto them as they do unto others. Target ELF offices and member's homes with firebombs. Target the members themselves with ball bats and/or shovels (whichever you find better), and hit their cyberspace property with the most vile viruses and worms out there. By bringing terror to these eco-loons, these spineless liberal losers could be stopped within a matter of hours.