People seem to be dancing around it, but the theory here seems to be that the FBI (or one of their assets) bombed Judi Bari and then they tried to frame it on her to associate the environmental movement with terrorism.
http://www.democracynow.org/2012/3/27/judi_bari_re...
http://www.democracynow.org/blog/2012/3/27/part_2_...
AMY GOODMAN: Why do you think? And what have you concluded after 20 years and making this film, Who Bombed Judi Bari?
DARRYL CHERNEY: Well, the FBI files on Earth First! go all the way back to 1981, when Earth First! was conducting civil disobedience against the secretary of the interior to stop some oil drilling leases, and they’ve—had been following us. They did a sting operation on Earth First! in 1988. The FBI tried to get Earth Firsters to literally blow up three nuclear power plants. They failed, because they realized that Earth Firsters would not associate themselves with bombs. And yet, it seems very clear that the FBI was intent on associating Earth First! with bombs, and that’s exactly what happened in our case. So they had a history of trying to discredit Earth First! really right out of the box.