TL;DR: If we take "silence is violence" seriously, then I am authorized to beat most of you up.
A video is going around with a bunch of white kids harassing some white woman outside a restaurant because she didn't make a BLM fist on demand. I have no idea how representative or common this kind of thing is; I suspect it was largely unique to this particular mob.
They repeat the slogan "Silence is violence".
From a strategic point of view, it's a beautiful slogan for few reasons.
If you get people to believe it, then they are forced/bullied/pushed/induced/conscripted/whatnot to join your side. Once somebody sincerely says, "Either you're with us or against us," you recognize that they are forbidding you from being neutral. Either you fight for them or fight against them. Either way, you have to fight. Threats backed with overwhelming force often work.
But it goes beyond that. By equating literally doing nothing with literal violence, you thereby authorize people in your own group to use violence as they see fit. Most people raised in a modern, liberal, tolerant, open, democratic society were taught that you may use violence defensively, not offensively. You may use it against perpetrators of violence, not against innocent bystanders. However, if you can convince yourself that innocent bystanders doing nothing are literally committing violence, then you are thereby authorized to use defensive violence against them. If eating dinner and not raising a fist when asked is violence, then you may punch back! Far from condemning this mob for acting like every other religious and struggle session mob throughout history, we should perhaps praise their restraint, as they didn't literally beat the hell out of this "violent" woman . Or, perhaps, we should condemn them for not responding to the violence of her silence with actual violence. Maybe this mob was too cowardly to stop her violent silence.
As a strategic matter, it's brilliant messaging for controlling your mob and others. But is the position correct?
It's easy to come up with cases where one is obligated to act rather than remain silent or to do nothing. You ought not pass by the drowning toddler when you can save him with little effort. You ought not let your colleague grope a grad student at a party when you can intervene, especially if it won't cost you your job. You ought to stand up for your friend when the bully pushes him, but the two of you outnumber and can take the bully.
But of course the world is full of injustice. Right now, people are literally enslaved. China is engaging in genocide or something close to it against the Uighurs. Myanmar's government is engaging in genocide against the Rohingya.
Some people are unaware of these things, though as far as I can tell, the typical person in the mob above is unlikely to regard ignorance of atrocity as an excuse when the news of the atrocity is easy to encounter.
If silence is violence, then, can we not condemn even more people--including most BLM protestors--for their silence and complicity in horrific evil? Note that I wrote two books and multiple papers in response to systematic violence against blacks in the US, so I am not being defensive here, and further, I share many of the BLM protestor's concerns. But that said, the crimes I just mentioned--slavery and genocide--are even worse than how the US's criminal justice system treats blacks. Alternatively, if we care about structural injustice, in terms of sheer overall loss of welfare, closed borders is worse than everything else by a couple orders of magnitude. Should we form a mob and intimidate any BLM protestors who don't make the open borders hand signal (I guess we'll need to devise one) on demand?
One might insist that the difference is that some issues are more salient or local.
I'm not sure what difference "local" makes except in cases where one can actually make a big difference. It's easy to save the drowning toddler in front of you, which is part of what makes it obligatory rather than optional. But beyond that, it's not clear to me why local matters. If it takes equal effort to stop a horrific injustice overseas or a less horrific injustice here, you should stop the injustice overseas. But we're not really talking here about stopping injustice. Getting some women eating dinner on a DC sidewalk to make a fist is not going to make a difference in reforming the police.
I'm also not sure how "salience" makes a difference. BLM is salient in part because the news covers this issue far more than it covers, say, the Uighur atrocities or the injustice of closed borders, and they cover it more in part because that's what people are protesting. Citing salience here is a bit like saying the topic you want to discuss is the most important because you happen to be discussing it. Nope.
At any rate, starting tonight, I plan to wander DC with a bat and beat up anyone who isn't already wearing a T-shirt proclaiming their disgust at the top 10 on-going injustices in the world today. Silence is violence, and I intend to stop the violence!
Personally, it turns out I complain the correct amount about all the injustices in the world, so I am not liable to defensive violence. The rest of you had better watch out, though.