It doesn't sound like the protestors were violent in this case. All they did was distribute leaflets outside someone's home. Obviously it was not a lot of fun for the engineer who was targeted.
Because if I read that pamphlet manifesto, it doesn’t come across as logical and rational - it actually reads more like “borderline unhinged radical”, and who knows what level of “restraint” is acceptable to such a person?
If I’m kept in my home by fear of such - I’m sure there’s a word that captures that, perhaps “imprisoned”, then to me (and in the case of false imprisonment, to the law), the fact that noone or nothing has been hurt or damaged doesn’t make things “non-violent”.