This is something I've seen tackled in comments before, but I thought it might be nice to try to get it together in one place, plus I had some time to kill. If you have anything you'd like to add or think I got wrong, please let me know.

• The alt-right coined the term "alt-right." It's their own name. "Alt-left" is a term of abuse coined by people outside of it. The term seems to have been coined in an attempt at symmetry, but the symmetrical thing to do, if we're calling the alt-right by its own name, is to call leftists by theirs. Names coined by leftists for themselves include "leftist," "socialist," "communist," "anarchist," and "syndicalist."

• It's clear what "alt-right" refers to, partly because it's an actual, self-defined movement, an online "alternative right" that essentially reconstitutes fascism/Nazism without openly embracing the existing symbolism of those movements. You'd expect "alt-left" to be the same thing the other way, right? But there is no movement called "alt-left," and there's nothing "alternative left" about online socialists; they're the same left that was around before the alt-right was so much as a twinkle in 4chan's eye, and they're not terribly interested in hiding it.

• The alt-right is a rejection of the conservative establishment, but there is no left-wing establishment for the so-called "alt-left" to be an alternative to. "Left-wing" and "establishment" are nearly antithetical in the first place, and the vast majority of leftists have no serious electoral option that even pretends to be on the left. They're only "alt" in the sense that the left itself is "alt" of capitalist parties.

• If we're going to start calling everyone who uses Internet memes alt-something, then there must be an alt-everything. This would make the vast majority of meme pages alt-center-right. Being on the Internet is not sufficient to be "alternative." At this point, it would be alternative not to use online platforms. This is not what's alternative about the alt-right.

• The alt-right is a largely cohesive movement. By extension, the "alt-left" must be, too, right? But the left is notoriously good at sectarian squabbling, and there's no prominent, cohesive leftist movement that I'm aware of, nor any tendency with a clear majority on the left. Which of the hundred-some-odd Balkanized leftist movements is the one being called the "alt-left," and why should anyone care when none of them have the ears of anyone in power?

Bonus: Why is there no "ctrl-left"? Well, the way the people define the term clearly refers to the US Democratic party and similar neoliberal parties elsewhere. So the "ctrl" part is probably fine, but the people being tarred with this label aren't part of the left to begin with. The other problem is that, if you look at what the people who use the term believe, most of them favor government control just as much as the Democrats, if only in different forms. It's a nonsensical term at best and in most cases a hypocritical one.

Self-described Homeland Security offices have been established across the United States and in several major states, including New York, Pennsylvania, Illinois, and California. A majority of New Jersey-based Homeland Security officers are affiliated with the anti-antifascist movement and are opposed to anti-fascism, anti-racism, and law enforcement reform.

In June 2017, a group known as the State of New Jersey Office of Homeland Security and Preparedness engaged in a propaganda campaign against Antifa, a loose network of anti-fascist groups. The group published anti-antifascist propaganda on their website, naming Antifa a terrorist organization.

The People's Commissariat for Aeronautics and Space has tasked a team of mathematicians with algebraic analysis of the anti-antifascist movement. After nearly a month of careful study, the Commissariat has announced the team's findings: the opposite of "anti-fascist" is "fascist." Upon reviewing these findings, the Central Committee approved the construction of mass drivers similar to those used to bombard ISIS with moon rocks in the months leading up to the siege of Raqqa; these will be used to return any immigrants found to have a connection to the New Jersey Homeland Security terrorist movement to the loving embrace of Earth's atmosphere.