President Barack Obama said the nation needs help from U.S. executives if it wants to successfully defend against an onslaught of hackers that have victimized mega-corporations such as Sony — but many of the big dogs in the tech world avoided the speech over unresolved concerns about former National Security Agency contractor Edward Snowden’s disclosures of secret government surveillance.

Obama said during a speech at Stanford University that Silicon Valley and financial services CEOs need to do a better job of sharing information more quickly with each other and with the government in order to keep a massive leak like the one that devastated Sony from happening again, according to a Reuters report. Obama said that the government “Cannot do this alone,” and neither can the private sector, as oftentimes it is the government that has the most recent information on threats that expose weaknesses in America’s cyber defenses.

Obama has made cyber security a top priority in 2015 after the high-profile hacking attacks. However, many top execs from the tech world — including those from Google, Facebook, and Yahoo — didn’t show up for his speech, as they are opposed to the administration’s leaked surveillance practices.

The attack on Sony had particularly grave ramifications, and the U.S. blamed North Korea for the attack, which eventually resulted in the initial cancellation of the film “The Interview” which satirically depicted an assassination attempt of North Korean leader Kim Jong Un. Obama said in an interview with Re/code that North Korea is not particularly good at hacking, which makes the successful attack on Sony all the more worrying, as China and Russia are far better at it.

He said during the speech that the only way to defense the United States from cyber threats is through a partnership between the government and industry, sharing information on a regular basis.

He met privately with some Silicon Valley business leaders — a relationship that has become strained after Snowden exposed extensive government surveillance practices.

The lack of reforms that have come from Snowden’s revelations are what prompted the CEOs of powerhouses Google, Facebook, and Yahoo to stay away from the conference. However, Apple, Paypal, Intel, Visa, and other companies were on hand.