Tumblr's history is not free of controversy—especially when it comes to changes over its content policies over the years.

The site is one of the most famous spaces for social justice and progressive thought on the web; but has also taken reeled in what it allows on the platform significantly over the years.

Here are a few pivotal moments to remember in Tumblr history...

2012: Tumblr Looks at Self-Harm Blogs and Launches PSAs

A scale.

In one substantial effort against triggering sensitive content, the Tumblr staff took a stand against the promotion of self-harm and eating disorders. The platform was careful to clarify that the move was not meant to target people with mental illness, but to prevent the glorification of dangerous behaviors.

The team wasn't perma-banning anybody who continued to post this content, but rather included public service resources interspersed throughout the search results for relevant keywords like "thinspiration".

This Tumblr policy change is considered by many to be a highlight in the Tumblr legacy as a whole. It was a results-oriented solution that sought to break a cycle.

Instead of being met only with images of self-harm or extremely thin women, users were seeing viable and relevant resources in exactly the right place.

Related: Does Social Media Do More Harm Than Good?

2018: The Tumblr Adult Content Ban

On December 3, 2018, Tumblr banned adult content. This site-wide ban that had many longtime users up in arms. It's known colloquially as "the Great Purge of 2018". If you were there to see it, we do not need to explain why.

Tumblr wasn't necessarily an adult content outlet before this policy change, but many loved the platform for the progressive, empowering attitude of the community when it came to things like sexuality.

Overnight, Tumblr became an entirely new place. The blanket ban shut the door on all types of adult imagery—videos, photos, GIFs, and even explicit drawings. Many educational images depicting anatomy were being flagged unfairly; even content completely unrelated to sex was targeted for containing things like rainbow flags.

Blogs found in violation by the Tumblr team were set to private automatically, and many innocent accounts were simply terminated outright. Life on Tumblr has never been the same since.

Read more: What to Do if Your Blog Is Flagged on Tumblr

2021: The New Tumblr iOS Rules

An iPhone booting up.

Just before the adult content ban, the Tumblr iOS app was actually removed from the Apple App Store. In 2021, the company took preventative action to avoid being removed again.

Related: Tumblr Bans a Long List of "Harmless" Tags

Tumblr's new policy for its iOS app censors content using a long list of flagged keywords and phrases—we won't link to it here (it's pretty heavy), but you can find it on Google easily. Some items on the list, like slurs and other harmful language in particular, are included for obvious reasons.

But others, such as sexual puns or euphemisms associated with things like narcotic use, have some bloggers biting back. The purpose of this overhaul is to prevent young users from accessing inappropriate or sensitive content through the app.

Banned words on the list now yield limited search results, preventing the posts that they're attached to from ever seeing the light of day.

Longtime fans have been quick to call out the fact that much of this list will do nothing but filter out totally harmless material, as well as posts that may otherwise end up being a life-saving resource for some users in peril. Tags like "binge", "PTSD", and "mental illness" are being flagged along with the rest.

Tumblr has always been an incredibly supportive community for those struggling with mental illness and isolation, however. The biggest concern is that this new policy will limit the conversation surrounding these topics on the platform.

Related: The Best Free Blogging Platforms

Tumblr Censorship: Public Discourse Will Never Be the Same

Were any of these Tumblr policy changes justified? We'll let you be the judge of that. Even Tumblr's harshest critics can probably attest to the value of a social blogging environment devoid of harmful triggers, imagery, and content.

It's an experience that ends up being much more enjoyable for everybody involved.