Check this out its about the "Dark Internet" in 2009 where most of this stuff originated but still isn't the first source. for Mariana's Web or CAIMEO.
Nov 26 2009 https://www.theguardian.com/technology/2009/nov/26/dark-side-internet-freenet
We don't find anything for 2009 or before but these private networks was around way before this just public didn't know much about Tor and few Networks before then. The core principle of Tor, "onion routing", was developed in the mid-1990s by United States Naval Research Laboratory employees, mathematician Paul Syverson, and computer scientists Michael G. Reed and David Goldschlag, with the purpose of protecting U.S. intelligence communications online. The alpha version of Tor, named 'The Onion Routing Project' or simply TOR Project, was developed by Roger Dingledine and Nick Mathewson. It was launched on September 20, 2002. If you search "Mariana's Web" from 2002 to 2009 you get these Results. https://www.google.com/search?q=mariana%27s+web&num=100&newwindow=1&biw=1455&bih=722&source=lnt&tbs=cdr%3A1%2Ccd_min%3A1%2F1%2F2002%2Ccd_max%3A1%2F1%2F2009&tbm=
You don't find anything for '7' years which is very interesting from the Tor released in 2002. We start to find things after 2010 but not before.
From here we can see how many people searched Mariana's Web and CAIMEO over all the years.
After this we want to look at Mariana's Web Searches between 2011 to 2015 just to name a few for now.
Mariana's Web Search [2011-2015]
Jun 6 2011 https://www.3gb.com.mx/forum/conversacion-casual/mi-experiencia-en-la-deep-web/
Dec 19 2011 https://answers.yahoo.com/question/index?qid=20111219152309AA8b51R
Jan 5 2012 http://ppcorn.com/us/top-5-unsolved-internet-mysteries/
March 3 2012 https://forum.bodybuilding.com/showthread.php?t=142827361&pagenumber=1
July 28 2012 http://www.ign.com/boards/threads/remember-deep-web.452597492/
Oct 30 2012 https://www.reddit.com/r/TOR/comments/12con0/does_anybody_actually_know_how_to_navigate/
Dec 10 2012 https://renantecnologiadainformacao.wordpress.com/tag/marianas-web/
Jan 20 2013 https://www.3djuegos.com/comunidad-foros/tema/18992280/0/deep-weeb-level-5-marianas-web/
June 10 2013 https://morizfa.wordpress.com/tag/marianas-web/
Aug 23 2013 http://forum.html.it/forum/showthread/t-1551110.html
Oct 5 2013 http://tordeepweb.com/2013/06/19/top-3-deep-web-myths-debunked/
Nov 8 2013 https://www.kaskus.co.id/thread/527b6401becb174d0a000000/quotdeep-webquot-the-real-internet-undeground/
Jan 1 2014 http://thefearmythos.wikia.com/wiki/Mariana%27s_Web
Dec 21 2015 https://www.reddit.com/r/conspiracy/comments/3xs2pp/marianas_web/
We wanted to know all about CAIMEO from 2012 to 2016 so we looked around
CAIMEO Search [2012 to 2016]
Jan 22 2012 http://gold-silver.us/forum/archive/index.php/t-58359.html
Oct 19 2012 http://www.millenniumforums.com/showthread.php?6803-The-Deep-Web
Oct 2012 https://pastebin.com/ERR514ud
Oct 19 2012 http://www.misteryinternet.com/2016/04/marianas-web-y-redes-clos-y-loky.html
April 4 2013 http://www.nolanfans.com/forums/viewtopic.php?t=13074&f=19
May 29 2013
June 3 2013 https://forum.bodybuilding.com/showthread.php?t=154479183&pagenumber=1
July 27 2013 https://www.neogaf.com/threads/its-become-aware-of-itself-were-going-to-die-do-you-think-this-could-happen.636041/
Sept 4 2013 https://www.unexplained-mysteries.com/forum/topic/254052-the-deep-web/
Oct 31st 2013 https://myanimelist.net/forum/?topicid=683803
Dec 31 2013 https://archive.4plebs.org/x/thread/13943166/
Nov 4 2014 http://www.dinarchronicles.com/news-alternate/level-4-information
Oct 8 2014 http://darkwhite666.blogspot.com/2014/10/tutti-gli-articoli-sul-deep-web-indice.html
Aug 19th 2015 https://www.reddit.com/r/deepweb/comments/3ewitj/is_the_caimeo_super_ai_a_real_thing_or_just_an/
Aug 23rd 2015 https://anastiel.blogspot.com/2015/08/table-of-contents-tesla-experiment.html
March 7 2016 http://www.fitmisc.net/forum/archive/index.php/t-89756.html
May 14 2016 https://yuki.la/x/17691461
July 21 2016 https://www.reddit.com/r/deepweb/comments/4twie7/can_anyone_identify_this/
Sept 2 2016 https://www.brainjet.com/random/2367160/13-real-life-x-files-type-mysteries-that-will-give-you-the-creeps/
Sept 29 2016 https://www.reddit.com/r/conspiracy/comments/554cdg/has_anyone_ever_heard_of_something_called_caimeo/
Oct 1 2016 http://scpsandbox2.wikidot.com/makta2
Oct 2 2016 https://www.reddit.com/r/deepweb/comments/55kz34/is_caimeo_a_hoax/
Oct 25 2016 http://ru.netstalking.wikia.com/wiki/%D0%AF%D1%80%D1%83%D1%81%D1%8B_%D0%B8%D0%BD%D1%82%D0%B5%D1%80%D0%BD%D0%B5%D1%82%D0%B0
Thanks for letting me share tell me what you think about it below if you want!