WhatsApp successfully appealed a ban that left millions of Brazilians without access to the messaging service. An order from judge Marcel Montalvão required the nation's mobile phone operators to block WhatsApp for 72 hours starting on Monday due to a dispute over access to communications related to a drug investigation. It was overruled Tuesday by a judge at a higher court, after WhatsApp appealed for a second time.

But even during the short time that Brazil's ban on the Facebook-owned app was in effect, people still found other ways to access the type of encrypted messaging features that triggered the block in the first place.

Several rival apps that offer encrypted messaging services reported a surge in Brazilian sign-ups, which highlights how the growing ubiquity of private messaging apps makes it hard to stop people from using them.

"My perception is that Brazilian users understand that there are more options out there, and that some of them offer a decent level of privacy and security," said Javier Pallero, a policy analyst who covers Latin America for digital rights group Access Now.

Viber, for instance, said it saw a big spike in messages and new members in the country.

https://twitter.com/Viber/status/727531772314030080

Meanwhile, Telegram said it has gained more than 1 million new Brazilian users. In fact, the company tweeted it was having trouble keeping up with the swell in demand.

WhatsApp is incredibly popular in Brazil, in part because it allows users to bypass expensive text messaging rates. The service is used for everything from large family group chats to doctors coordinating their responses to the Zika outbreak. The company boasts 100 million Brazilian users. That's half of the nation's entire population who were left at least temporary digital casualties of the latest global policy battle over encryption.

The latest ban isn't WhatsApp's first in Brazil. A different court had ordered a similar ban in December, also in response to a criminal investigation. That too, was quickly overturned. Telegram also reported a similar flood of new users then. And in March, Diego Dzodan, Facebook's vice president for Latin America, was also briefly detained due to a court order from Montalvão that cited WhatApp's failure to comply with criminal subpoenas.

Throughout this crackdown, WhatsApp has said it can't turn over the data the government wants because it simply doesn't have it. The service started rolling out end-to-end encryption -- a technology that protects users' messages so that only the sender and recipient can unlock them -- in 2014, and last month announced that it was now available for all platforms.

Civil liberties groups have heralded the expansion of strong forms of encryption that companies themselves cannot unlock as a boon for everyday users, but law enforcement has warned that the technology may help criminals and terrorists escape justice by "going dark." In the United States, Apple and the Justice Department had a recent legal scuffle over the issue -- and legislation introduced by senators Dianne Feinstein (D-Calif.) and Richard Burr (R-N.C.) last month would require  companies to help to unscramble encrypted communications for the government if passed. 

But privacy advocates say those sorts of mandates would be almost impossible to enforce because many encrypted messaging products are made by developers overseas or by open source projects that post their code for anyone to see online and lack a central point person who could be forced to comply.

The flood of new users to other apps that offer encrypted messaging in the wake of the WhatsApp ban in Brazil only seems to bolster that point: Even if one service goes dark, there are more waiting in the wings.