Document ID: ./input/supremecourt_opinions/opinions/23pdf/23-411_3dq3.pdf
Page Number: 7

2 

MURTHY v. MISSOURI 

Opinion of the Court 

I 
A 
With their billions of active users, the world’s major so-
cial-media companies host a “staggering” amount of content 
on their platforms.  Twitter, Inc. v. Taamneh, 598 U. S. 471, 
480 (2023).  Yet for many of these companies, including Fa-
cebook, Twitter, and YouTube, not everything goes.1  Under 
their  longstanding  content-moderation  policies,  the  plat-
forms have taken a range of actions to suppress certain cat-
egories of speech.  They place warning labels on some posts, 
while deleting others.  They also “demote” content so that it
is less visible to other users.  And they may suspend or ban
users  who  frequently  post  content  that  violates  platform
policies.

For years, the platforms have targeted speech they judge
to be false or misleading.  For instance, in 2016, Facebook 
began  fact  checking  and  demoting  posts  containing  mis-
leading claims about elections.  Since 2018, Facebook has 
removed  health-related  misinformation,  including  false 
claims  about  a  measles  outbreak  in  Samoa  and  the  polio
vaccine  in  Pakistan.  Likewise,  in  2019,  YouTube  an-
nounced that it would “demonetize” channels that promote
anti-vaccine messages.

In 2020, with the outbreak of COVID–19, the platforms 
announced  that  they  would  enforce  their  policies  against 
users who post false or misleading content about the pan-
demic.  As early as January 2020, Facebook deleted posts it 
deemed false regarding “cures,” “treatments,” and the effect
of “physical distancing.”  60 Record on Appeal 19,035 (Rec-
ord).  And it demoted posts containing what it described as
“conspiracy theories about the origin of the virus.”  Id., at 
—————— 

1 Since the events of this suit, Twitter has merged into X Corp. and is 
now known as X.  Facebook is now known as Meta Platforms.  For the 
sake of clarity, we will refer to these platforms as Twitter and Facebook, 
as they were known during the vast majority of the events underlying 
this suit.