"History has shown us that sacrificing our right to privacy can have dire consequences -- we still live in a world where all people are not treated equally. Too many people do not feel free to practice their religion or express their opinion, or love who they choose," said Cook, who is among the highest-profile business leaders to publicly identify as gay.
"If those of us in positions of responsibility fail to do everything in our power to protect the right to privacy we risk something far more valuable than money -- we risk our way of life," Cook said. "Fortunately, technology gives us the tools to avoid these risks."
The decision by the CEOs of Google, Facebook, and Yahoo to skip the summit was seen by some as a snub on behalf of an industry frustrated by the pace of reform to government surveillance activities programs revealed by former National Security Agency contractor Edward Snowden.
A group of major tech companies, including Apple, formed the Reform Government Surveillance Coalition in December 2013, urging Obama and Congress to place limits on U.S. surveillance and data collection programs.
In a speech last year, Obama agreed in principle to some limits on spying programs, including the bulk collection of domestic phone records. But the administration has primarily favored legislative action, which has so far yet to succeed.
Instead of waiting for Congress or executive action, tech companies have taken it upon themselves to harden their digital defenses by expanding their deployment of encryption to secure their customers' communications. But this has set up a conflict with some federal law enforcement agencies, which worry that such features may make it harder to combat the increasingly digital nature of national security threats and crime.
“I think it’s fair to say that changes on the technology front have outpaced governmental and legislative efforts,” said Andrew Crocker, a legal fellow at the Electronic Frontier Foundation, a civil liberties group.
U.S. government surveillance activities are seen as a potential long-term financial liability for the tech industry, which has customers around the world.
“Seventy to 80 percent of the user bases for a lot of these companies are the foreigners who get very little protection under our system,” Cato Institute senior fellow Julian Sanchez said. “If they don’t display some push-back, they know they won’t do very well with those markets.”
Cook also took some thinly veiled shots at the business models of competitors in the tech space during his remarks.
Many of the "free" services from Internet-based tech sites, such as Facebook and Google, rely at least partially on targeted advertising made possible by culling through information collected about users' online activities.
Cook's focus on privacy during the summit was in contrast to Obama, who spent more time highlighting the threat of malicious hackers. While noting that people could "rightly ask" about the safeguards in place to prevent the government from intruding on their privacy in light of new technological capabilities, Obama emphasized the need to protect systems from other cyber-threats.
Obama signed an executive order Friday encouraging companies to share cybersecurity threat information, part of a larger effort to beef up the nation's cyber infrastructure in the wake of a string of high profile cyberattacks on U.S. business and government agencies in recent years.