Rio de Janeiro - Brazilians awoke to a day without WhatsApp Thursday after a judge ordered the popular messaging app blocked throughout the country for 48 hours.
The reason for the order was murky because it arose from criminal proceedings in Sao Paulo state that are being kept under judicial secret.
However, Mark Zuckerberg, who heads WhatsApp's parent company Facebook, indicated in a Facebook post that the case was related to the company's attempt to guard customers' data.
Also read: Zim pastor appears in court over placard denouncing Mugabe
In a statement, Sao Paulo's criminal court system said only that WhatsApp had been handed two prior judicial orders this year that the California-based company failed to heed.
"Because even then the company did not heed the judicial decision, the public prosecutors' office requested the service be blocked," the court's statement read.
The popularity of WhatsApp and other messaging apps has hurt cell phone operators, who have seen revenue from SMS messages plummet as consumers come to rely increasingly on free services like WhatsApp, which is estimated to have around 100 million users in Brazil.
However, the union representing Brazil's cell phone service operators, SindiTelebrazil, denied in a statement the companies were the plaintiffs in the case.
Zuckerberg called the blockage "a sad day for Brazil," adding that the company is working to get it reversed.
"Until today, Brazil has been an ally in creating an open internet. Brazilians have always been among the most passionate in sharing their voice online," Zuckerberg's said in his post. "I am stunned that our efforts to protect people's data would result in such an extreme decision by a single judge to punish every person in Brazil who uses WhatsApp. "
While WhatsApp users in Brazil are still able to open the app, their messages are not being sent.