Scientists are bearing the brunt of this, but it is very much everyone's problem. The people being harassed are doing things we urgently need them to do. That includes things like warning us about about immediate dangers, telling us what precautions we need to take, and doing research that could lead to workarounds and solutions to the problems themselves.
We need to speak against this. We need to act against this. And we need to change the system to provide protections and remedies. Otherwise we are all going to suffer.
Speaking does not stop those who are willing to harass and intimidate those who are working to improve our world. They cannot be reasoned with because they are categorically unreasonable.
I will leave what actually DOES work to your imagination. Cowards are cowardly.
I think you underestimate the degree to which they are cowardly. They gain confidence from superior numbers, but one-on-one, or crowd vs crowd, a lot of them can be put off by speech or other non-violent means. I think that deep down a lot of them know what they are doing is wrong, even though they tell themselves otherwise.
Non-violent resistance has a long history and has often been effective. As an example, the fight for civil rights was not won because the progressives usually managed to beat up the racists. The progressives were largely non-violent. The racists were routinely violent, but they still lost.
It takes a lot of bravery to oppose someone who may try to hurt you. Some of us will get hurt. It shouldn't be necessary, but if we want this to stop we will have to take some risks. (There's nothing wrong with avoiding high-risk situations, but some risk is necessary.)
Personally, I am also okay with defending yourself if you are attacked. Non-violence is always better, but I doubt I could remain passive if faced with physical violence.
All of your points are absolutely valid because it's definitely difficult to find the gumption to stand in the way of raucous bastard.
Once you find it, it just becomes a righteous way to become the raucous bastard.
Dont get me wrong, I'm no billy badass that goes looking for trouble, but SOMEBODY has to do it - and after the first guy does it, you'd be surprised how many somebodies will help.
I love chaos, and will gladly spend the night in jail, or a couple weeks in a cast to cause the people who inflict fear to become fearful. It's the only way they learn.