6 successful tech companies that are surprisingly secretive about their internal workings

Last year, more than 1,000 Google employees protested Google's secretive plans for a project called Dragonfly, in which Google planned to develop a search engine for China that would follow the country's strict censorship laws.

Read more: Everyone wants to work at Google — but we found out how 15 ex-Googlers knew it was time to quit

Google employees wrote a letter stating that they did not have the information they needed to make an ethically informed decision about their work, project, and employment. Business Insider reported that a handful of employees left Google over the dispute.

In the past, Apple has been known for being very careful about sharing inside information with the general public.

Back in 2013, several examples came to light regarding the extreme measures Apple took to ensure secrecy.

When the iPad was being developed, Apple made its developers chain their devices to their desks. Developers of the iPad sat in a room with no windows and changed the locks so only select individuals could enter the room.

"They had these custom frames built around them so we couldn't even tell what the iPads looked like," an iPad developer told Business Insider in 2011. "We could plug into them so we could code to them and we could touch the screen and play with that, but we couldn't see the form factor."

However, this year, some major Apple leaks made their way into the public. For example, several leaks from Apple's supply chain showed the company's plans for their 2020 iPhones, along with videos and images.

Famous VC Peter Thiel is one of the cofounders of Palantir, a $20 billion dollar data-analytics company.

Palantir works with various organizations of the US government such as the CIA, FBI, branches of the military, and the Department of Defense, and has kept its work notably quiet.

"That's because many of its customer agreements include non-disclosure clauses due to the nature of their work," Business Insider's Rosalie Chan wrote in July. "As a result, Palantir tends to keep a low profile, sharing almost no information about how its software is used or its own finances."

But the company's veil of secrecy was lifted in July after news outlets reported on Palantir's work with US Immigrations and Customs Enforcement. WNYC reported that ICE agents use information gathered by Palantir's software during workplace immigration raids.

Although the connection to ICE spurred protests against the company among employees and activist groups, Palantir defended its work, and has remained supportive of the government.

Renaissance Technologies is no newcomer to the tech world, having been founded in 1982, but its technology remains a mystery.

This successful quantitative trading hedge fund keeps details close to the vest. Its use of math and computers continues to amaze yet puzzle the investment world.

Renaissance Technologies is known for its secret methods, formulas, and equations that are used to predict market fluctuations. Individuals with non-financial backgrounds such as mathematicians, physicists, statisticians, and others create the formulas and keep the information confidential.

The company's methodologies may remain secret, but its success is hard to dispute.

As if Elon Musk isn't doing enough already, the entrepreneur recently announced his new startup Neuralink, which is working to develop ultra-high-bandwidth brain-machine interfaces to connect humans and computers.

Neuralink is currently focusing on creating small chips that contain tiny flexible threads to be implanted in the human brain, allowing the brain to connect directly with computers. During Musk's company presentation, he described the technology as a "symbiosis with artificial intelligence."

Musk claims that the first prototype will be implanted in a person by late 2020. While there is much chatter about the startup, there is not much public information about how the task will actually be accomplished.

The company already has $39 million in funding from investors, but Neuralink will face several regulatory hurdles to make its technology come to life. In the meantime, it's pushing through with animal trials.

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