In 1998 we had a fire at the Vail Ski Resort with and estimated $12 million. The fire destroyed three buildings and four chair lifts. Four Ecoterrorists were indicted for these fires. So, there is history of this sort of thing.
http://archive.adl.org/learn/extremism_in_the_news/Other_Extremism/eco_vail_indictments.htm?LEARN_SubCat=Extremism_in_the_News
Vail was set by ELF.