Facebook has changed its terms of service, meaning 1.5 billion members will not be protected under tough new privacy protections coming to Europe.
The move comes as the firm faces a series of questions from lawmakers and regulators around the world over its handling of personal data.
The change revolves around which users will be regulated via its European headquarters in Ireland.
Facebook said it planned clearer privacy rules worldwide.
The move, reported by Reuters, will see Facebook users outside the EU governed by Facebook Inc in the US rather than Facebook Ireland.
It is widely seen as a way of the social network avoiding having to apply the upcoming General Data Protection Regulation (GDPR) to countries outside the EU.
The change will affect more than 70% of its more than two billion members. As of December, Facebook had 239 million users in the US and Canada and 370 million in Europe.
Facebook also has 1.5 billion members in Africa, Asia, Australia and Latin America, and they are the ones affected by the change.
Users in the US and Canada have never been subject to European rules