Wikipedia is a Tome of Eldritch Lore.And no you can't escape it.
Wikipedia is ruled by Big Brother.It's obvious and admitted. We have never been at war with Uncyclopedia 
Wikipedia is in fact Brainiac.The fifth The Dark Tower book has the characters fighting robots based on Doctor Doom. This indicates that the Marvel Universe exists somewhere out there in the Multiverse. Since Marvel characters have occasionally crossed over with DC characters, it follows that The DCU also exists. Finally, since Roland and Eddie in The Dark Tower visit the real world, it logically follows that any character from the DCU would also be able to access reality. Superman's enemy, Brainiac, exists to acquire all knowledge in the universe and then destroy it so no new knowledge can appear. Wikipedia is currently doing an excellent job of amassing every piece of data on Earth into one single entity; other planets with their own Internets presumably have similar projects going on. (This refers to the Brainiac from Superman the Animated Series.)
Alternatively, Wikipedia is the Brainspawn's Infosphere.◊ Infosphere! Just look at the logo! And the Brainspawn, too, want to amass all the knowledge of the universe and then destroy it. This also means that the WikiVandals are the Philip J. Frys of our time. Bless their superior, yet inferior, brains.
Wikipedia is the embryonic form of Skynet/The Source.You only have to look at the combinatorial-tastic mass of rules to see how close it is to becoming self-aware.
Orlando Jones' character from the 2002 The Time Machine Movie is WikipediaThis is semi-canonical to anyone who watches the movie nowadays. He's probably only an AI platform that dispenses Wikipedia's information. That's why he was so eager to show the main character information on Sci-Fi instead of actual science. (We all know what's happening to the "Reality/Fiction information ratio" in Wikipedia.) He didn't believe in time travelling when he was reactivated in the future because he doesn't accept original research.
Wikipedia is a Integrated Data Sentient EntityQuoting the third chapter from the Suzumiya Haruhi No Yuutsu novels, when Yuki explains to Kyon what she really is: "In the vast sea of data known as the universe, there exist many highly sentient data entities that possess no corporeal bodies. These entities started out in the form of pure data. As all sorts of data gathered together, they became sentient, and finally they evolved by collecting other data. As they exist only as data and have no corporeal bodies, they cannot be detected even with the most advanced optical devices. As old as the universe itself, they expanded along with it, and the relative database became ever wider and larger". Just replace universe with Internet, data entities with Wikipedia translations, and pure data with Wiki entries. Furthermore, as Wikipedia is just a bunch of data stashed in a hosting site, Wikipedia is visible only as a website; also, though Wikipedia is not as old as the Universe itself, it does expands along with human civilization, and that site's database becomes ever wider and larger — you can download Wikipedia's entire database as a 4 GB zipped archive!
Douglas Adams wrote a parody of Wikipedia before Wikipedia was startedThe titular 'organisation' in The Hitchhiker's Guide to the Galaxy sounds suspiciously familiar to the modern reader. The Guides themselves are electronic encyclopedias with imperfect and rewritable info.
Wikipedia is secretly getting all its information from TV TropesThe database of TV Tropes is more extensive than many would think. Of course, most of the info is then deleted for not having Citations.
Wikipedia will become the main source for information by 2050People will reference Wikipedia constantly, even in classes, and its information content will be considered on par with those of textbooks.
The following characters are Wikipedia administrators:
Jimbo Wales is a Timecop.Isn't it obvious?
Wikipedia is not sinister in any way, shape, or formThought this was funny enough to add. Would be pretty weird if it was true, though.
Wikipedia is sentient, and all the other Wikis and similar sites are Split Personalities
There is a cabalThe Cabal is a sort of ersatz sentient being composed of the editors and administrators' worst personality traits, like GLaDOS, but that's never hindered ersatz evil beings in the past. The Ouendan and the power of positive thought will destroy its evil grip.
The Tvtropes Wikipedia page is written by the Mac ad writers
Wikipedia is in fact the building blocks for the creation of a real-life Guide.Wikipedia is the actual content. The physical Guide itself has manifested in the form of the Amazon Kindle.
Wikipedia requires articles to not be written from an in-universe perspective because it would lead to the events of Tlön, Uqbar, Orbis Tertius .In the story, an article in an encyclopedia is written about the country of Uqbar, which doesn't exist. And in Uqbar, there's stories about Tlön, which doesn't exist. By the end of the story, earth is becoming Tlön. Clearly, Wikipedia, with its high readership and comparatively low submission requirements, would be an ideal medium in which to create worlds.
Every new edit on Wikipedia creates an alternate universe in which the edited contents of the article are true.It stands to reason that the contents of an edited Wiki page aren't the same as the pre-edited contents, and therefore both cannot be simultaneously true. However, each article is purportedly true, and it can be assumed that said article is true until the point where it's replaced by an edited version. Each edit thus spontaneously creates a new universe which is closer to 'perfection' than the prior universe, which continues to exist as a lesser reality when compared to the new one since the 'error' (as designated by the fact it was edited) was never corrected. Of course, this means that each universe, having an 'error' purged through the editing of Wikipedia, is that much closer to being a perfected universe. When the Wikipedia is perfect, so shall the universe be perfected. And then, dunno, maybe Instrumentality.
Everything on Wikipedia is an intricate lie.Reality has been transformed by Wikipedia. Nothing contained in the site is true, and is completely made up so they can dominate the future and control the world and the minds of its inhabitants.
Wikipedia is or contains Lilith...while TV Tropes is Adam. Wikipedia records the materialistic and objective of our lives (the Lilim) while TV Tropes records the subjective aspects of everything (Angels, AT Fields).
Wikipedia is the afterlifeAll the articles? The souls of people (some may wonder around for a while, but they all end up in Wikipedia. There, the souls suffer for eternity, and when you think you got used to the pain it strikes again ten times stronger. You have to bear that for all eternity. And everyone ends up there.
Wikipedia is all edited by one person.
Wikipedia is an omniscient AI.There are no editors; Wikipedia edits itself. And the AI has tapped itself into the internet, allowing it to access websites, and to simoutaneously create pages on Wikipedia. 
Wikipedia was created by aliens......As part of a mission to learn about human lifestyle and culture without direct interaction!
Jimbo Wales is actually Willy on WheelsBecause wouldn't it be really funny if Jimbo Wales was actually the most famous vandal in Wikipedia's history?
Wikipedia and TvTropes are secretly madly in love with each other (the sites themselves, not their editors) but both of them Cannot Spit It OutDon't act like you can't see all the Belligerent Sexual Tension between them.