WhatsApp co-founder Jan Koum on Monday put out word that he is leaving Facebook, which bought the smartphone messaging service four years ago for $19 billion.

Facebook's new focus on protecting private user data is likely to change the game for many campaigns, making it harder to deliver highly targeted, personal political messages.

Facebook reports quarterly results Wednesday as it grapples with a data privacy scandal that strikes at how the huge social network makes money from what it knows about people.

The Russian-American academic who developed an app that allowed political consulting firm Cambridge Analytica to farm the data of 87 million Facebook users faces questions Tuesday by British lawmakers.

A personal finance expert who appears regularly on British television launched legal action on Monday against Facebook, claiming it had published more than 50 fake posts bearing his name last year.

Facebook announced Wednesday it would begin rolling out changes to how it handles private data this week to comply with forthcoming EU rules, with European residents seeing the measures first.

A US federal judge in California ruled Monday that Facebook will have to face a class action suit over allegations it violated users' privacy by using a facial recognition tool on their photos without their explicit consent.

Facebook took out full-page ads in European newspapers Monday to trumpet tough new EU legislation that promises "more data protection for you", as the company seeks to win back trust following a damaging privacy scandal.

The new law, set to come into effect on May 25, aims to give users more control over how their personal information is stored and used online, with big fines for firms that break the rules.

Sensing the Facebook scandal has shifted the transatlantic winds, the EU is asserting itself as a forward-looking regulator rather than a retrograde bulwark against Silicon Valley's innovative might.

After years of mounting concern, the European Union will introduce tough new data protection rules next month, which Facebook chief Mark Zuckerberg himself has welcomed in the face of the latest scandals. 

A Moscow court on Friday ruled to block the popular messaging app Telegram in Russia, after it refused to give state security services access to private conversations.