On Thursday a Brazilian judge ruled that WhatsApp should be unblocked following 12 hours without access to the service.

A lower court ruling ordered telecoms companies to block the messaging app, which has around 100 million users in Brazil. The Sao Paulo court insisted on a ban due to the fact that WhatsApp would not hand over information relevant to a criminal case, writes Jenny Barchfield for The Associated Press.

Brazil Brings WhatsApp Back Online After Block

State judge overrules WhatsApp blocking

That case is sealed, meaning that details are thin on the ground. Local media reported that the investigation involves the most powerful drug gang in Brazil. WhatsApp was brought back online after state judge Xavier de Souza overruled the lower court.

He released a statement in which he explained that “in light of constitutional principles, it doesn’t seem reasonable that millions of users are affected because of the inaction of the corporation” to provide information to the court.

Facebook founder Mark Zuckerberg, who also owns WhatsApp, said that the case was due to the company’s policy of guarding user data. “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,” Zuckerberg wrote in a Facebook post.

“Until today, Brazil has been an ally in creating an open Internet,” he added. “Brazilians have always been among the most passionate in sharing their voice online.”

Telegram, Viber gain users during 12 hour outage

Brazilian telecoms firms have regularly complained about lost revenue due to the popularity of free services like WhatsApp, and they did not oppose the ban. However a spokesman for the SindiTelebrazil telecoms association denied that the group was a plaintiff in the case.

Social media companies such as Facebook, WhatsApp and Twitter have huge amounts of users in Brazil. Many users frustrated by the ban moved to competitors such as Viber and Telegram.

While technology companies often fall foul of Brazil’s complicated legal system, this is the first time that a major service has been blocked all over the country. According to company data WhatsApp is used by nearly half of the Brazilian population.

The lower court revealed that WhatsApp had ignored two judicial orders earlier in the year, leading to the blockage. “The company did not heed the judicial decision, the public prosecutors’ office requested the service be blocked,” the court’s statement read.