Don't make threats (also don't kill people, it's usually wrong). It is too easy for Power to amplify and harness sincere backlash against your movement and whip it into counter progress outrage.

At a consultation stage don't threaten lives and infrastructure. Ask how the company will protect against sabotage and vandalism.

Are they building infrastructure that is vulnerable to ecoterrorists? If an ecoterrorist were to attack their pipeline with a high powered hunting rifle would it be an ecological disaster?

If a saboteur spread diamond grit abrasives on the rail track the coal cars travels on, would that cause damage, a derailment, or just increase maintenence costs? What about grease?

If seepage from the tailings pond was spread onto the plant manager's lawn, would he let his kids play there?