| A huge proportion of Brazil's online population use WhatsApp - partly because making mobile calls is expensive |
For the third time, a Brazilian judge has blocked nationwide access to the messaging service WhatsApp, say Brazilian media.
WhatsApp also faces fines of 50,000 reais (£11,700; $15,300) per day until it complies with the judicial order.
Facebook, which owns the application - enormously popular in Brazil - says it does not store conversation archives.
The most recent blockage happened in May, and forced 100 million people to turn to alternative services a huge proportion of the internet-using population in a country with some of the world's highest mobile phone charges.
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Correspondents say it is the latest clash in a battle between tech firms and judicial systems over how to collaborate in criminal investigations without compromising individual freedoms - like in the dispute between Apple and the FBI over access to the phone of the San Bernardino gunman.
Twitter users responded with frustration - and, in many cases, with parody:
"The order was not complied with, despite being issued three times," said Judge Daniela Barbosa de Souza in her Rio de Janeiro court, according to the Folha de Sao Paulo news website (in Portuguese), "thus requiring the adoption of coercive measures determined by this judgement."
According to the Folha, the judge sought to have the contents of conversations sent in real time to investigators - as is the case with intercepted phone calls.
But end-to-end encryption - introduced in April - is a key advantage touted by WhatsApp.
In its website's frequently asked questions, it says: "Privacy and security is in our DNA, which is why we have end-to-end encryption in the latest versions of our app... [This] ensures only you and the person you're communicating with can read what is sent, and nobody in between, not even WhatsApp."
But the judge counters that big tech firms need to abide by national laws, and if WhatsApp has the technology to encrypt messages, it should also have the technology to pass on judicially required information.
Technology commentators suggest the regular interruptions to service could dent WhatsApp's popularity.
As with before, the blockage probably will not last more than a few days but, at this point, people may just tire of dealing with the WhatsApp vs. Brazil feud altogether," remarked thenextweb.com.