Google Allo should be deleted and never used, says Edward Snowden

‘Don’t use Allo,' tweeted Mr Snowden

Snowden speaks via video link during the Athens Democracy Forum at the National Library in Athens yesterday (EPA)

Edward Snowden has warned people not to use Google’s new chat app, because it lets the company read everything that they say.

Google has finally released its new chat app after showing it off over the summer. It comes with a robot that watches everything people say and then stores it for later analysis, using that data to improve the app itself.

But that also means that chats are stored on Google’s servers indefinitely, and are able to be read by it. The company had initially indicated that the messages would only be stored temporarily, limiting the possible impact of any data breach and retaining some privacy for users.

But it now appears that Google won’t be doing that after all. Instead it will keep hold of all conversations.

Google will use that data to improve parts of the app, such as its smart replies feature. That will allow the app to read through conversations and try and work out how people talk – it can then use that data to suggest what they might want to say to their friends.

But Google would presumably also be able to use that same data at a future date to target ads at users. Since their personal conversations might include some of their most sensitive data, that could lead to prying of a kind that most people would object to.

Making the change does probably keep Google on the right side of the law. By keeping track of all messages, Allo conversations will be accessible by law enforcement with warrants – something that can’t happen on apps like iMessage or WhatsApp, both of which have run into trouble over not being able to give up information to authorities.

All of those problems led Mr Snowden to send out a flurry of tweets telling people not to use Allo.

“Free for download today: Google Mail, Google Maps, and Google Surveillance,” he wrote. “That's #Allo. Don't use Allo.”

Another read: “What is #Allo? A Google app that records every message you ever send and makes it available to police upon request.”

Snowden already called Allo "dangerous" after it was revealed at Google's I/O conference earlier this year.

Google does allow people to switch into a different mode, called Incognito, where conversations will be end-to-end encrypted so that they can’t be read by Google. But that isn’t turned on by default and leads most of the app’s features to break, turning it into just a conventional chat app.

"We've given users transparency and control over their data in Google Allo," said a Google spokesperson. "And our approach is simple – your chat history is saved for you until you choose to delete it. You can delete single messages or entire conversations in Allo.

"We also provide the option to chat in Incognito mode, where messages are end-to-end encrypted and you can set a timer to automatically delete messages for your device and the person you’re chatting with's device at a set time."