Cook has posted the letter on a new Apple security microsite that explains how Apple uses people’s personal information, how it collects it, and why. The site's publication and Cook's letter follow promises made by Apple earlier this month that it would step up security and privacy measures.
"We’re going to make sure you get updates here about privacy at Apple at least once a year and whenever there are significant changes to our policies," Cook wrote.
Cook added that "trust means everything to us" and reassured consumers that Apple respects privacy and protects it with "strong encryption, plus strict policies that govern how all data is handled".
The Apple boss also takes the opportunity to criticise free internet service providers and social networks (which include Google and Facebook), in particular their selling on of data to advertisers.
"A few years ago, users of Internet services began to realise that when an online service is free, you’re not the customer," he wrote. "You’re the product. But at Apple, we believe a great customer experience shouldn’t come at the expense of your privacy."
Privacy, he said, is a key component of Apple’s software and hardware design. "We don’t build a profile based on your email content or web browsing habits to sell to advertisers. We don’t 'monetise' the information you store on your iPhone or in iCloud. And we don’t read your email or your messages to get information to market to you. Our software and services are designed to make our devices better. Plain and simple."
He also reassured readers that - unlike Google, Facebook and their ilk - Apple had not and never would work with "any government agency from any country to create a backdoor in any of our products or services. We have also never allowed access to our servers. And we never will."
Last month, an alleged 101 iCloud users had explicit images stolen and sold by hackers, although Apple argued this was not due to a security breach on its part. Victims included actress Jennifer Lawrence, Downton Abbey actress Jessica Findlay-Brown and model Kate Upton.