Because, Peace, justice, and a healthy environment are threats to corrupt politicians. Labeling environmentalists as terrorists is simply a tactic to evade the open debate of environmental issues by those who have no rational arguments to support their opposition to protecting the environment . They cant be stopped until governments with spine are elected, but that can't happen because corporations have all the money and media.
This is actually very true. Environmental protest is a very dangerous activity. The environment is everything that makes the good surrounding around us. Therefore we have to protect the environment and avoid the environmental protests in order to the enjoy the nature and what the environment provides. Thi is very vital.
Environmental protest is excellent in theory, but weak in practice because it puts participants at significant risk for injury. This was indicated recently when a Dakota Pipeline protestor severely damaged her arm as a result of her activities. She isn't the first, and unfortunately she is far from the last.
If a person owns a piece of land, they have a right to do things on it that are legal. This is the case if the person next to them, or down the street, approves of it or not. It becomes anarchy if people start to believe that they have a right to interfere with the legal use of property of others.