Multiple stuff, on many fronts.

For example, 20 years ago, the few individuals who would read news online would go to the websites and blogs of their choosing directly. The material they read was under their influence. But now for most adults in the U.S., social media outlets like Facebook decide what news they can read, according to a Pew Research Center survey.

Facebook currently has more than 2 billion active users per month. This makes Mark Zuckerberg, the CEO of the company, the un-elected president of the world's largest country.

Google, the undisputed ruler of web search, which processes more than 5 billion queries a day is another illustration. Its name has become a verb, literally. To answer their questions about everything, people trust it.

This immense amount of power has made these corporations into information gatekeepers and we have to trust them to use their power equally and responsibly. For instance, if Zuckerberg chooses to turn evil and misuse his authority to send users false and deceptive content, there is practically nothing to stop him. Or if Google tries to manipulate search results to support its own bottom line to the detriment of its rivals, nothing can be done by others.

Not all is that. There was a time when start-ups were able to change the technical environment and drive fresh ideas into space. In reality, according to this same theory, Google, Facebook and Amazon, still very young businesses, all rose to power and are now among the five largest tech companies and the most successful companies in the world. Their growth, however has made it more difficult to replicate their success. They must either embrace being acquired or endure a slow and humiliating death for other startups who dare to walk in the footsteps of Facebook, as the giant uses its user base and nearly infinite supply of cash to clone their features and steal their audience.