In the EQG Holiday Special, Sunset figured out that Anon-a-Miss was actually Scootaloo, Sweetie Belle and Applebloom.
But what if things happened differently?
What if Sunset never figured out who Anon-a-Miss really was?
What if her friends refused to listen after her little chat with Twilight?
For those who haven't seen it, the comic can be read here:
https://www.youtube.com/watch?v=2-MMfsFt2NE

Sunset and her friends had no idea that Anon-a-Miss was a plot to break them up. They had no idea that it was targeting Sunset. When Apple Bloom was outed as Anon-a-Miss the account had leaked all of one secret, and everyone believed it was simply a younger sister having fun at her older sister's expense.

They certainly had no idea Apple Bloom would respond to Anon-a-Miss' failure by resorting to a Plan B that had all the subtlety of a Plinian eruption and all the precision of a hurricane.

What they do know is that in one night the veil of secrecy around magic at CHS was obliterated when a video of Sunset Shimmer, with full demonic transformation, doing physically impossible things exploded across the internet.

Now they have to prepare for the fallout, even though they have no idea what form that will take.

When you become unexpectedly popular for writing a story in a certain genre, you end up being exposed to more and more of what's in that genre, and your imagination runs away with ideas you encounter as a result, and suddenly what was meant to be a topic you touched for one or two stories at most instead becomes a mainstay of your corpus.

I was most definitely not looking for a new Anon-a-Miss fic. I've got two that have already been released and two in the oven, which makes four that I need to finish. I had no particular desire to start number five.

Then I encountered this idea. The idea in short:

Anon-a-Miss falls apart almost immediately with almost no damage done, which you would think is like dodging a bullet given how the genre tends to go, but because the underlying cause isn't dealt with it doesn't avoid the problem at all. It amplifies it by having Apple Bloom resort to releasing the one bombshell secret that was originally so far off the table it wasn't even considered.

Here's why it interested me enough to start up a new story:

The idea of the magic at CHS being exposed to the world presents seemingly infinite possibilities in itself, but there's also the fact that Anon-a-Miss occurs at a key juncture in the timeline. The human Twilight Sparkle is already on the case. If nothing major changes then you get The Friendship Games but changes could result in things that range from full blown apocalypse to her equipment never malfunctioning in the first place.

Credit must be given:

Uria came up with the idea at five AM with the help of fatigue and Pringles. Even now, as we speak I type this, a shadowy group of individuals are operating in a loose coalition in an attempt to bring that idea, kicking and screaming as it may be, into some form of reality and then unleash it upon the world.

This story is emphatically not the fruit of that particular labor. This is just me writing my version. That is, in part, why this isn't called "Your Past Is Here To Stay"; I wanted that title to be reserved for the official version created by the collaborating cabal.

None the less, this is inspired by Uria's idea, the first chapter extremely so, and credit must be given. Also, given my ties to the currently undisclosed syndicate working on the official realization of Uria's idea, there will probably be a fair amount of cross pollination between this story and the eventual "Your Past Is Here To Stay".

Anon-A-Miss has become a plague on the halls of Canterlot High. Students are on the brink of a fight every day and tensions are rising in order to stomp out Anon-A-Miss before the winter break.

With no-one in Canterlot High to turn to, Sunset Shimmer braves it alone and decides to pull out her old blackmailing tools in order to get the job done. It might be illegal, but it's the school's last hope for order to be restored.

A solo Anon-A-Miss story.

Diamond Tiara is ambitious. She's also the editor of the School Newspaper. The biggest story to hit is the Anon-A-Miss scandal. When evidence falls into Diamond Tiara's lap, it would be the start of something great as a partnership is born.

Anon-A-Miss has been wreaking havoc all over Canterlot High. Secrets are spread and trust is broken. The Rainbooms go to confront their 'friend' Sunset Shimmer, but are surprised by what they find instead.

This story is a sequel to One Day I Found a Multiverse in My Pajamas

The word has spread. The message is clear. It doesn't matter whether or not Sunset is Anon-a-Miss; all that matters is that everyone at Canterlot High believes she is.

Well, mostly everyone. One girl's been out of class since before the drama started, but surely she's going to follow suit.

One of the stranger tangents of the Oversaturated World.

It's Christmas time at Canterlot High. Normally a time for fun and cheer. But no this year it seems. Someone is spreading people's worst and most embarrassing secrets.

Their name? Anon-A-Miss. And the one that seems to be the culprit? Sunset Shimmer. At least according to Applebloom, Sweetie Belle, and Scootaloo.

Unfortunately for whoever is doing it, Canterlot High isn't falling for it. Not after the Battle of the Bands. And even the few that still haven't fully forgiven Sunset for her past bullying, believe she is innocent.

But then, who is the culprit?

Sunset is desperate so she asks Twilight for help. She receives a box that will get the truth out, by force if necessary. Slight crossover with "Star VS. The Forces of Evil".

The Applebloom, Scootaloo and Sweetie Belle of Equestria are not fillies that give much thought to their ideas and make plenty of mistakes.

What if during the Anon A Miss incident, on Earth, one of their counterparts makes a foolish mistake of her own? Besides the plan itself?

When Anon-A-Miss struck, Sunset found herself alone. Even her friends have abandoned her. Twilight Sparkle asks her to come to Equestria to avoid Anon-A-Miss and goes to confront her friends. Together, they determine if Sunset is guilty or innocent.