Prominent tech leaders spoke out against Facebook over the weekend, about a week after reports surfaced that the social network leaked user information.

Tim Cook called for "well-crafted" regulations that prevent users' data from being collected and applied in new ways without their knowledge during a session at the China Development Forum in Beijing on Saturday. "The ability of anyone to know what you've been browsing about for years, who your contacts are, who their contacts are, things you like and dislike and every intimate detail of your life--from my own point of view it shouldn't exist," Apple's CEO said, according to Bloomberg.

Meanwhile, Elon Musk on Friday deleted the Facebook pages for SpaceX and Tesla, noting on Twitter that the one for his electric car company "looks lame anyway."

Cook's and Musk's comments follow The New York Times and The Observer of London's report that Cambridge Analytica, a political data company launched by Stephen Bannon and Robert Mercer, collected users' Facebook data and claimed it could influence the behavior of American voters. Mark Zuckerberg and Sheryl Sandberg both issued statements days after the revelations were made public, but by the weekend, some felt that the company's leadership wasn't remorseful enough for the leak.

On Sunday, Zuckerberg took out several full-page ads in British and American newspapers to apologize for a "breach of trust" in the Cambridge Analytica scandal. "I'm sorry we didn't do more at the time," read the ads that appeared in The New York Times, The Washington Post, and the U.K.'s The Observer, among other publications. "We're now taking steps to ensure this doesn't happen again."

The company's share price has taken a beating in the wake of the scandal. Facebook's value plunged by nearly $50 billion last week.