I do not believe letting the victims deal with these problems alone will lead to a solution. If change is to occur, the actions of these people must be denounced to show that we as a community do not agree with what they are doing.
Do you honestly think 99% of us saying in unison that this thing is wrong will stop the 1% from doing what they're doing?
F*** no. They do it because they know they can control people with it and know they'll never go to jail. Beyond that, they truly do not care what we think. You're naive to think otherwise.
If this person just wanted to scare and control people then why would s/he go out of their way to target such a specific group. If they didn't care what other people thought, why would they be taking a political stance. If their only goal was to get people riled up without getting caught, then why provide so many self identifying details.
This person is putting themselves at risk because they believe that society would be better off without a feminist view. They think that their extreme actions will silence a outspoken opposition, and s/he probably believes they are being heroic for doing so.
and yes, I do believe by showing support for the victims you are dissuading people from further extreme action.
You do not have to agree with me, and I certainly will not resort to name calling to try and shame you into agreeing. However I do not believe that people do bad things just because they can get away with it, I do believe there is always a motivation.