In an action set to rankle privacy and encryption advocates, a judge in Brazil ordered mobile phone operators to shutter the WhatsApp chat service for three days, according to The Intercept.

The ruling was put into effect on May 2 when an estimated 91 percent of Brazilian mobile users, or 100 million people, were unable to use the service, which enables users to communicate for free.

The case is believed to stem from a ruling two months ago by the same judge ordering Facebook, WhatsApp's parent, to cooperate in a drug case. A Facebook vice president was jailed for a day – for failing to provide encrypted information stored on a cell phone – before another court overturned the order.

WhatsApp said it is incapable of providing users' communications because the end-to-end encryption denies all but the user access.