The answers were somewhat varied.
"I don't know of specific cases where we have been stolen from by the government," Apple CEO Tim Cook said. "I know of no case [of] ours where it occurred ... I can only speak to firsthand knowledge," he added.
Google CEO Sundar Pichai initially followed his lead. "I have no firsthand knowledge of any information stolen from Google in this regard," he said. (Pichai later issued a correction, acknowledging a China-linked cyberattackon Google in 2009 in which the company said some of its intellectual property was stolen.)