There's a kind of mentality among these kids (most of them are kids) that may have been fostered by their growing up in an age dominated by terrorism and extremist rhetoric.

The idea that protest, even if peaceful, won't be noticed unless it's extreme, is one part of it. The other part is that anyone who isn't actively protesting is part of the problem. That these people driving to work in the petrol cars etc are in fact working for the oil industry and just as guilty of climate destruction as the oil corporations themselves. A kind of "If you were walking/cycling to work, we wouldn't be blocking you. So it's your own fault." type of thinking. As in the 70s. when many Communist or Anarchist students I knew accused me of being a Tory, or even a fascist, because I believed, and still do, that a properly-regulated private sector can contribute usefully to society and that police are needed in any society.

Daft buggers, some folk!