Last night, Twitter abruptly changed the way its block function works. 

Changes like this one are normal -- social media platforms frequently make sudden changes and then go into turtle-mode until users stop complaining. Which is why what happened next last night was so unusual: in the face of immediate, vocal outcry from Twitter users, the company reversed the change.

You can stop reading right there if you don’t want to get into the minutiae of what the changes were and why they mattered, but I think that part’s actually pretty interesting too.

OK, so, historically, if you blocked me on Twitter, I could not interact with you at all. I couldn’t retweet your tweets, I couldn’t send you a direct message. But also, I wouldn't be allowed to subscribe to your tweets. They wouldn't show up in my feed. The only workaround I could use to see what you were tweeting would be to go directly to your page, assuming it was public.

Last night’s changes briefly made it so that the last part -- the part of blocking that canceled my subscription to your feed -- no longer held. If you blocked me, I was banned from pestering you with @ replies or direct messages. But your tweets would show up in my feed and I could rebroadcast them to my followers.

People who didn’t understand last night’s outrage think that this is a pretty slim distinction to get angry about. Take the worst case scenario, which is that you block me after I’ve harassed you. Why would the new rule changes matter? Do we really believe in the existence of a harasser noncommittal enough to be deterred by the small obstacle of having to go directly to your Twitter page?

Those people actually do exist, and I know some of them. Two of my childhood friends had mental breaks in their twenties. The stories are similar, so here’s one.

The summer after college, one of my best friends had a mental break. He started to believe that people were talking to him through his walls. He called me for advice.

I couldn’t convince him that these might be hallucinations, but because we were close, I was able to persuade him to talk to his family about the problem of the break-ins, and I called them first so that they’d know what was going on. He got treatment: therapy and medication. Frustratingly, neither helped much.

He’ll be fine for awhile, and then he’ll become fixated on someone he knows on Facebook or GChat. He’ll send them message after message with questions about conspiracies involving murder and rape. If people talk to him about it, he’ll often decide that they’re in on the conspiracy. Sometimes he’ll threaten to kill them.

We stopped talking after he threatened to kill me. Not because I thought he would, but because it seemed like talking to me had become a trigger that made things worse for him. I was like a TV show that aggravated him, and when I turned myself off, he calmed down.

I still worry about him, and I try to stay connected without aggravating him. Which really just means that I talk to his parents to see how he's doing. And when he messages our friends, those friends usually call me to ask what to do.

In every case, I tell them to block him on Facebook and GChat. Without fail, just removing that source of stimuli - their lives are no longer being broadcast into his - calms him down. He stops threatening them.

This doesn’t make literal, technological sense. These people still exist online, they’re still eminently findable. If you block someone on chat, they can still email you. If you unfriend someone on Facebook, they can go to your Twitter account. But he doesn’t do that. For no good reason, closing those two avenues solved the problem. It doesn’t make sense, it just made everyone feel safer, and cut down on some of the noise for my friend.

My only point here is that human relationships are vast and strange. Which means that when you make a tiny change to your social platform, it will have effects beyond your imagination. That’s why I’m glad Twitter listened. People told them they hated this change that maybe barely seemed like a change at all. And rather than saying, “Look, we know how tech works, and you’re wrong and you’ll get used to it,” they took us all at our word.