“Mainsewer media” (or “main sewer media”) is a term for the “mainstream media” (MSM) that has become a figurative “sewer” instead of a “stream.”
   
“Main Sewer Media” was posted on Twitter by Determined on September 12, 2009. “truth you will not get from main sewer media” was posted on Twitter by Keith Westbrook on July 21, 2010. “MSM = Main Sewer Media” was posted on Twitter by beyaself on February 18, 2017.
     
“Mainsewer Media” was posted on Twitter by Shadow-Banned Dan on September 26, 2014. “mainstream/mainsewer media” was posted on Twitter by own3d on February 20, 2018. “It’s rather ‘mainsewer media’” was posted on Twitter by Jaroslaw Szeptycki on April 2, 2018.
   
   
Wikipedia: Mainstream media
Mainstream media (MSM) is a term and abbreviation used to refer collectively to the various large mass news media that influence many people, and both reflect and shape prevailing currents of thought. The term is used to contrast with alternative media.
     
Twitter
Determined
@FrazzledHaloz
RT @JohnSWright49 I see the Main Sewer Media is ALL OVER the March on DC….NOT.
7:26 PM · Sep 12, 2009·Twitter Web Client
   
Twitter
Keith Westbrook
@kcjw33
truth you will not get from main sewer media
Sherrod had Just Won Big Discrimination Suit Against Feds | The FOX Nation http://shar.es/mPX3M
9:40 PM · Jul 21, 2010·Twitter Web Client
 
Twitter
Shadow-Banned Dan
@NextVoiceUHear
Replying to @ChuckNellis
@ChuckNellis To the Mainsewer Media a beheading in America of an American by a Muslim will be news after, say, the 20th or the 50th.
3:31 PM · Sep 26, 2014·Twitter for Android Tablets
       
Twitter
Conservative Party of Fl.
@CPofFl
Carson: I Didn’t Say Anyone Can’t Legally Run For Office, Just Who I Would Support http://breitbart.com/video/2015/09/23/carson-i-didnt-say-anyone-cant-legally-run-for-office-just-who-i-would-support/ Main Sewer Media lies as off again
1:44 PM · Sep 23, 2015·Twitter Web Client
   
Twitter
Let’s find out.
@Orbosterva
Replying to @PrisonPlanet
I guess the main sewer media is realizing it is time to start sucking up to the new counter culture, if they want to survive.
3:05 PM · Feb 15, 2017·Twitter Web App
 
Twitter
beyaself
@beyaself1
#nottheenemy
MSM = Main Sewer Media
3:40 PM · Feb 18, 2017·Twitter Web Client
 
Twitter
own3d
@own3d75
Replying to @LTCPeterLerner @ronenbergman and 2 others
RB is terrible liar… mainstream/mainsewer media
2:18 AM · Feb 20, 2018·Twitter Web App
 
Twitter
Jaroslaw Szeptycki
@JaroslawSzepty1
Replying to @OrwellNGoode
It’s rather “mainsewer media”.
12:15 AM · Apr 2, 2018·Twitter Web Client
     
Twitter
Gymnosperm
@glehman11
Replying to @abbydphillip @JohnKingCNN and @CNN
CNN is the tallest pipe for the main sewer media.
11:00 AM · Jan 12, 2021·Twitter Web App
 
Twitter
Jason Bourne CIA
@bourne_cia
Replying to @auntdiggie and @mjgranger1
No it is not approved. Mainsewer Media is lying to everyone saying it is fully approved. It is not.
10:43 AM · Aug 24, 2021·Twitter Web App
     
Twitter
big hit
@bighit64014374
Replying to @JonCover2 and @QueenofBaconz
Main sewer media. Stream sounds clean like brook or creek. Sewer is a more appropriate.
8:03 AM · Nov 8, 2021·Twitter for iPhone
 
Twitter
ApePitagorica
@ApePitagorica
Replying to @GuidoCrosetto
The front page of almost every newspaper. Do you need any more evidence that the entire mainstream (main sewer) media is propaganda paid for by you know who?
5:14 AM · Dec 20, 2021·Twitter for Android