As Facebook reels from the scandal over hijacked personal data, a movement to quit the social network has gathered momentum, getting a boost from a high-profile co-founder of the WhatsApp messaging service acquired by the huge social network in 2014.

As Facebook reels from the scandal over hijacked personal data, a movement to quit the social network has gathered momentum, getting a boost from a high-profile co-founder of the WhatsApp messaging service acquired by the huge social network in 2014.

"It is time. #deletefacebook," Brian Acton said in a tweet, using the hashtag protesting the handling of the crisis by the world's biggest social network.

The WhatsApp co-founder, who now works at the rival messaging application Signal, posted the comment amid a growing uproar over revelations that Facebook data was harvested by a British political consulting firm linked to Donald Trump's presidential campaign.

"Delete and forget. It's time to care about privacy," he said.

Several websites offered tips on how to quit Facebook, while noting that the process is more complicated than it appears.

Facebook offers users the option to "deactivate" an account for users who want to take a break and return later, or to "delete" the account and its data entirely.

But Facebook noted that some data such as posts on friends' timelines might remain in the system even after an account is deleted.

And longtime Facebook users could face complications on dealing with log-ins and authorizations to other websites and apps through the social network.

The website The Verge published a guide to deletion, advising users to download a copy of all personal data including photos and posts before quitting.

The website noted that it could take up to 90 days to fully delete an account, and that data may be inaccessible during that period.

Users may also face choices on what to do about other Facebook-owned properties such as Instagram, WhatsApp and Messenger.

It was unclear how many users were following through on plans to quit Facebook, which has more than two billion users worldwide.

But Roger McNamee, an early investor in Facebook, said the social network was losing the trust of its users.

"The issue is a callous disregard for the privacy rights of users and a lack of care with respect to data that had been entrusted to Facebook," McNamee told National Public Radio.

"I'm not sure exactly what's going on here, but I'm afraid there is a systemic problem with the algorithms and the business model of Facebook that allow bad actors to cause harm to innocent users of Facebook."