Why is Mastodon Growing?

Mastodon is a decentralized Twitter alternative growing fast. What is driving its growth?

[trigger warning: sex work, sexualization of children]

Mastodon is only one player among the many that work using the open OStatus or the newer ActivityPub standard. Among those, however, it’s the most popular and growing pretty quickly, with over one million accounts in less than two years. That’s nowhere near Twitter’s numbers, but pretty impressive for a free software developed by one person.

Mastodon has a lot of different types of servers, or instances as they are called, but few are as popular as the instance run by the main developer. It seems that there are a few reasons that drive the growth of the other popular instances. These reasons are related to how the centralized social media services, especially Twitter, operate – and cultural reasons related to sexuality.

One of the bigger Mastodon instances is Switter.at, which calls itself the “sex work friendly social”. Its creation can be traced back to changes in US law, to the bill known as SESTA/FOSTA, a combination of “Stop Enabling Sex Traffickers Act” (SESTA) and “Allow States and Victims to Fight Online Sex Trafficking Act” (FOSTA). These no-doubt well-meaning laws tried to prevent trafficking, especially trafficking children, but because they were badly written, they had other consequences as well.

The more serious consequence is that people probably died because of that bill, but it also had the side-effect that suddenly online platforms and websites were responsible if somebody used them for sex trafficking. No platform wants to face those charges, so websites started removing anything risky, including all kinds of sex work. Twitter was among the sites that started banning sex workers. Sex workers no longer had safe places where to exchange information or advertise for clients – until somebody set up a Mastodon instance meant for sex workers. Because it was outside US, SESTA/FOSTA didn’t stop it from operating. Switter grew quickly, attracting 56,000 users in a month. It is currently one of the most popular instances, with over 89,000 users.

Another reason for Mastodon’s growth is also related to sexuality. Two of the biggest instances are based in Japan. Together they have more than 500,000 users. Even the smaller one is bigger than the main instance run by the lead developer of Mastodon.

Twitter is really popular in Japan, but it has pretty strict rules on what kind of content it allows on its platform. There is one specific form of content that is popular in Japan, but routinely banned by the US-based moderators of Twitter: lolicon. Ethan Zuckerman has a good explanation of what lolicon is:

In Japan, there’s a distinction between 児童ポルノ – child pornography – and ロリコン – “lolicon”, short for “Lolita complex”. Child pornography is illegal in Japan and seeking it out would be deeply socially unacceptable. Lolicon, which includes animated cartoons and 2D drawings of young men and women in a way that is undeniably sexualized, sometimes through explicit depictions of sexual acts, is legal, widespread and significantly accepted. As Matthew Scala writes, “If you like ロリコン then you’re a nerd, but that’s not a big deal. It is legal and popular and sold in bookstores everywhere. I cannot emphasize enough that ロリコン is not only legal but really acceptable in Japan. It’s merely nerdy. On the other hand, if you like 児童ポルノ then you’re an evil sicko monster, and 児童ポルノ is highly illegal.”

Twitter removes lolicon from its platform, so fans of lolicon needed another way of sharing that kind of content.¹ One of the big Japanese websites for artists, Pixiv, started a Mastodon instance, and very quickly there were more Japanese Mastodon users than from any other country – 52 % of all Mastodon users when writing this text. Pixiv was already very popular, so people using it started sharing their art, including lolicon, on Mastodon.

In both cases Mastodon’s popularity seems to be related to how Twitter operates, especially in relation to laws and norms about sexuality. When users aren’t allowed on Twitter, they seek out other platforms that are more permissive. Mastodon instances are easy to set up and can be run from countries that have more permissive laws. Because each instance is run by different people, they get to set the terms of use on their platform. If users don’t like the terms on one instance, they can always find another one. This is why Mastodon attracts users from communities with cultures that are not allowed on more mainstream social media.

1. I’m not defending lolicon or trying to justify its existence. The fact is that it does exist and seems to explain at least some of Mastodon’s popularity. I’ll leave explaining the norms around lolicon to someone who understands Japanese culture better. ↩