When Twitter banned Milo Yiannopoulos, a tech editor for the conservative news website Breitbart.com who used the Twitter handle @Nero, Yiannopoulos reacted with characteristic modesty. He told the New York Times the ban launched “the beginning of the end for Twitter.”

Oddly, Yiannopoulos may be right. In February, the social media platform announced its Trust and Safety Committee. With Orwellian overtones, CEO Jack Dorsey tweeted, “Twitter stands for freedom of expression, speaking truth to power, and empowering dialogue. That starts with safety.” The San Francisco startup invites all comers to post their thoughts by name or anonymously. The more outrageous the tweets, the more attention they attract. Unbowed, Twitter HQ gets all sanctimonious when trolls get nasty. Like, who knew that would happen?

Conservatives knew that the Twitter panel, comprised of left-leaning organizations, would target the right. Their suspicions were confirmed when Twitter promptly shuttered the account of Robert Stacy McCain, an antifeminist blogger. Twitter would not disclose which tweets led to McCain’s ostracism. Likewise, Twitter won’t stipulate which tweets were the reason @Nero had to go on Tuesday.

In the brave new world of social media, no one talks on the record. No social media platform discloses which actions specifically led to a user’s banishment. They give lip service to transparency, then hide behind their platforms and their doublespeak.

So when I asked Twitter why it exiled @Nero, I got a vanilla statement emailed by a spokesperson who told me nothing and did not want to be named. I have to assume that Twitter talked to Buzzfeed, which reported @Nero was banned because he had “incited his followers to bombard ‘Ghostbusters’ star Leslie Jones with racist and demeaning tweets.” The nasty racism unleashed in those tweets drove Jones off Twitter.

As a private company, Twitter has the right to refuse service to unwanted individuals and set standards of acceptable discourse. Its prohibition on “hateful conduct” reads: “You may not promote violence against or directly attack or threaten other people on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or disease.” That’s a reasonable standard as long as it is applied fairly, or at least fairly most of the time. But there is nothing fair about the Trust and Safety Committee, a collection of left-leaning groups weaned on the expectation that institutions will protect them from the sharp elbows of partisan brawling.

Yiannopoulos is a provocateur, a gay, alternative-right conservative who lives to push others’ buttons. When a lefty group gets his “Most Dangerous Faggot Tour” banned from campus, it’s like throwing him a steak. A shameless self-promoter, he flogs their intolerance, because, well, they are extremely intolerant.

The proof is in the Twitter lifetime @Nero ban. Note that Twitter did not exile Yiannapoulos for anything he wrote, but for what his fans wrote. As the website Recode reported, Twitter booted Yiannopoulos because he was “one of the main instigators. He tweeted that Jones was ‘barely literate’ and also referred to her as a man.” The “barely literate” was in response to a grammatical error in a Jones tweet. (Who among us is without sin?) Jones is tall and strong, hence the dig at her feminity. I don’t defend those remarks. I endure worse on a regular basis. So if Twitter wants to ban users for relatively tame criticism, it’s going to become a lonely site fast.

If Twitter can derail someone for what his or her followers do, then why not eject Black Lives Matter leaders for inciting the rogue Baton Rouge cop killer? That’s where guilt by association leads.

We all know that won’t happen. This is left versus right. This is liberals deciding what conservatives should be allowed to say. More conservatives will leave Twitter, and more liberals will think that everyone agrees with them because their views are reinforced on the Twitter loop. It’s easy to tout civil discourse when you’ve muzzled your opponents. My guess is many liberals will nod in agreement with this column, but they won’t do anything about it because they’ll think Yiannopoulos deserved to be banned. And that’s the end of Twitter.

Debra J. Saunders is a San Francisco Chronicle staff writer. Email: dsaunders@sfchronicle.com Twitter: @DebraJSaunders