A Brazilian judge has ordered mobile networks operating in the country to block access to WhatsApp for 72 hours in a move likely based on the services use of encryption technology to prevent third parties (including law enforcement) from accessing messages.

Its the second time in five months that Brazil has taken action against the popular messaging app, which has around 100m users in the country. The first ban, which lasted for 48 hours, occurred in December 2015, with “failure to cooperate with a criminal investigation” cited as the reason.

This time, no reason has been publicly given due to legal secrecy surrounding an ongoing case in the northeastern state of Sergipe, but industry experts have suggested that it has been triggered by a similar case, with the situation possibly exacerbated by WhatsApps recent introduction of end-to-end encryption.

WhatsApp has said that it is “disappointed” by the decision, which will apply to Brazils five main mobile operators, and that it has cooperated fully with the state court during the investigation.

“This decision punishes more than 100m Brazilians who rely on our service…in order to force us to turn over information we repeatedly said we dont have,” said a WhatsApp spokesperson in a statement.

At least one party will be celebrating the WhatsApp ban however – rival service Telegram has reported a surge of downloads in Brazil after the block came into place.