Internet Incorporated

Adam: Mr. Van Statten owns the Internet.
Rose: Don't be daft, nobody owns the internet.

Henry Van Statten: And let's keep everyone thinking that way, right kids?

—Doctor Who, "Dalek"

In Real Life, the Internet is a network of networks. While a few aspects of it are centralized (for instance, the allocation of blocks of IP addresses, the top-level parts of the DNS, and the allocation of Autonomous System numbers), it mostly works in a decentralized fashion, where each system operates independently and their interconnections are based on bilateral agreements and common protocols. There is no central company, organization, or government agency which controls or operates the Internet as a whole.

In fiction, it does not have to work that way.

Instead of the decentralized Internet we are used to, the network all the characters interact with is owned and/or controlled by a single organization. This organization can be a powerful antagonist if the protagonists are hackers or are trying to uncover some secret it wants to keep hidden. Often, the Internet Incorporated is the creator of the Applied Phlebotinum which powers the Cyberspace the characters use—or is the one who stole it from its creators.

Note that this isn't technically impossible for fiction set in an alternate universe, but in Real Life, it's not true .

Examples of Internet Incorporated include:

Literature

The World Web from Hyperion is run by the AIs. They have some legitimate claim to this since it happens to be their home.

Live Action TV

Henry Van Statten from Doctor Who claimed to own the internet.
In Corner Gas Oscar was tricked into beliving that at a central authority had kicked him off the Internet.
Mocked on The IT Crowd, where the geeks play a prank on their boss by convincing her that "the internet" is a small Black Box with a blinking red light on the top. It's usually kept in Big Ben and presided over by "The Elders of the Internet".

Manga and Anime

Serial Experiments Lain: Tachibana Labs
Dennou Coil: Megamass owns the Augmented Reality system overlying the town of Daikoku. This is justified since it's a local system restricted to that town only, with the company having chosen (and presumably been permitted to) use the town as a prototype testing ground: They control The Metaverse, but not all the information said Metaverse connects to.

Tabletop Games

Cyberpunk 2020: Internet Phone Corporation ("These guys don't use the Net. They own the Net." With an elaboration that one of the most powerful paramilitary security corporations around still pays its bills to Internet on time. "You don't even want to guess what Internet can throw at you. It even scares Saburo Arasaka.")
Op Net from the Aberrant Tabletop RPG is the system that esentially replaced the internet (due to better Applied Phlebotinum) and requires its users to be licensed.

Video Games

In Deus Ex, it's revealed that the Ancient Conspiracy made a 'bottleneck' in the internet and all digital communications called the Aquinas Hub: All information that flows on internet, phone lines, satelites, anything digital, passes through that hub and can be filtered and monitored by whoever's in control of it. The end of the game is devoted to preventing the Big Bad from joining with an AI that has been granted control over this system, which would effectively make him God of the Internet.

Real Life

Real Life: America Online used to work this way. Fortunately the wonders of network effects forced their transition into a relatively normal ISP and the resulting demise of "AOL Keyword" on movie trailers and whatnot.
- As alluded to above, VeriSign operates 2 of the 13 root nameservers, including the A nameserver, and (after acquiring and spinning off Network Solutions) operates the only registry of .com, .net, and .org addresses for the various registrars.
  - There are alternative root nameservers out there. In purely technical terms escaping Veri Sign's clutches is as easy as setting up a new set of servers and moving over.
Also a callback to the bad old days of the Bell System, where one company pretty much did control the whole network, with few exceptions.
Now there's talk of giving the President of the United States the authority to control the use of Internet in the times of crisis, potentially capable of cutting off the connections from entire continents.
- Wont work if those continents made preparations. At best he might be able to cut the US from the network.

Web Comics

In Sarah Zero, the internet has been deleted and replaced by the corporation-controlled Contranet.

Western Animation

The Fairly OddParents once had Timmy give a Hurricane of Excuses for how he got cool-looking clothes by saying first the Internet, then inheritance, and finally going with "I inherited the Internet!" It's shown in a later episode (told from Chester and AJ's point of view) that neither one of them believes it, and AJ even explains to Chester that the Internet can't be owned by one person. He should know. He's tried.
In the South Park universe, the Internet is a giant Linksys router in a bunker somewhere.