404 - NOT FOUND 

Normally an error given when indicating that the client was able to communicate with the server, but the server either could not find the file that was requested, or was unwilling to fulfil the request for it and did not wish to reveal the reason why.
More recently used to describe a user or individual that, at any given moment will lock up and seem to have no intelligence what-so-ever and will not co-operate to solve an issue. (ie No Intelligence Found)

hey guys we got a 404 - NOT FOUND over here, user cant find ALT on the keyboard

404 - NOT FOUND by txtrlikesun April 2, 2006

404 Not Found 

The screen of death

Oh shit, I just typed my website wrong and it says "404 Not Found". I hate the internet.

404 Not Found by Ashabeth October 20, 2008

404 Not Found 

404 Not Found is the completely fucking retarded screen that comes up whenever you're looking for a good porn trailer.

AWW, SHIT! I GOT THE FUCKING 404 NOT FOUND CRAP AGAIN AND LOST MY PORN!

404 Not Found by worn.down April 25, 2010

Error 404 not found

Your love life you fucking incel

“How would you describe my love life with four words?”

“Error 404 not found”

Error 404 not found by murkerlurker December 27, 2019

Derivation: the "404: Not Found" error encountered when surfing the web. 

You've reached the end of the Internet. You may now shut down your computer and go outside.

There's nothing more to see here.

Derivation: the "404: Not Found" error encountered when surfing the web. by shill August 2, 2005

Error 404 (Not Found)!!1 

Head/Title message of Google's (and their own services such as YT, Gmail, Blogger, Gstatic, Google Photos) 404 page.
!!1 = They piss off at you.
To piss them off more, search any of their sneaky stuff they intend to hide (like Sundar Pichai getting testified, him bending his knees to CCP, Susan Wojcicki banning of anti-CCP wordings, Google's company secret leaked by some conservative media) after leaving the page. Google's tracker will start to slowly shadowban you at this point.

Error 404 (Not Found)!!1 The requested URL / was not found on this server. That’s all we know.

Error 404 (Not Found)!!1 by Shiine-1 May 2, 2022

404 Error: Not Found 

We're deeply sorry, but the definition for the term you were looking cannot be found. Please refresh the page for a chance to load the definition. This problem may have been caused by a lack of internet connectivity, or by the server being down for maintenance.

404 Error: Not Found. For more information, please visit our homepage at h t t p s : / / w w w . y o u t u b e . c o m / w a t c h ? v = d Q w 4 w 9 W g X c Q

404 Error: Not Found by Esteban AF May 7, 2018