Facebook is on a collision course with global intelligence agencies after making its popular mobile phone messaging service harder to crack than ever before.
Messages will be encrypted on WhatsApp, which has more than a billion users who can send messages, pictures and recordings over their phones via the internet.
It means that customers can send messages without worrying that they may be being spied on.
But while the move will be welcomed by some, others fear it will play into the hands of terrorists and criminals who could use the platform to map out their plans. The encryption turns messages into indecipherable computer code, which can be unscrambled only when it reaches the intended recipient.
That means they cannot be tapped by authorities – or anyone else – even if Facebook is handed a court order.
Jan Koum, WhatsApp’s co-founder, who grew up in Soviet-era Ukraine, said: ‘The desire to protect people’s private communication is one of the core beliefs we have at WhatsApp and for me it’s personal.
‘I grew up in the USSR during communist rule and the fact that people couldn’t speak freely is one of the reasons my family moved to the United States.’
The move has added fuel to an already raging row between technology firms and the US government over privacy.
Last month, Apple had a showdown with the FBI when it refused to crack an iPhone belonging to one of the gunmen responsible for a mass shooting in San Bernardino.
The FBI tried to force Apple to give it access to the device – but the technology company refused on the grounds that it would open the floodgates for security breaches.
The matter was settled when the FBI managed to crack the phone itself – but not before it created a huge political row over how much access technology companies should grant intelligence agencies.
Facebook boss Mark Zuckerberg told a conference in Barcelona that he was ‘pretty sympathetic’ with Apple’s position.
WhatsApp was bought by Facebook for $21.9 billion (£15.6bn) in 2014, even though it did not make a profit at the time.