Clarifying further, 'terrorism' means using fear (the 'terror' part) to achieve political goals (the 'ism' part). Peacefully blocking a highway might be civil disobedience, but it's nowhere near terrifying.
To clarify further, I could call my landlord a terrorist because he'll come banging on my door if I don't pay him on time. That induces fear, yet I think we can all agree my landlord is not a terrorist for wanting to collect his rent.
"Terrorism" is a laughably flexible term that could be used to fit just about anything given the right wording.
If you have to resort to calling someone a terrorist in order to get me on your side, you've failed to state why I should agree with you without resorting to FUD.
The protestors are using fear (the fear of being attacked by police) to achieve a political goal (somewhat murky but the general gist seems to be to accelerate the depolicing of cities).