Edward Snowden warned people not to use Google's Allo chat app because the company can read everything they say to their friends, family and colleagues, he alleged.
The whistleblower wrote: "Free for download today: Google Mail, Google Maps, and Google Surveillance," he wrote. "That's #Allo. Don't use Allo," on Twitter, alongside a number of other messages that warned people not to use the app.
Google Allo stores conversations so it can analyse them and then Google will present relevant content from its network, whether adverts, content on Google search or YouTube to the user. It will also analyse the language used in conversations and use this to predict what people want to say and how they want to say it to their friends.
Although the app is designed to offer users a more tailored experience, critics including Edward Snowden thinks storing this data is against human rights.
At first, Google said the data would only be stored temporarily to protect the privacy of some users, but now it seems the company has changed its mind and will be storing the private chats indefinitely.
By storing this data, it also means the information can be used, if needed by governments and other official bodies to help fight crime. Because the information is held on Google's servers, those investigating into illegal activity, whether terrorism, organised crime or other malicious acts can use a warrant to force Google to reveal the conversations between suspects, which is not possible with other free messaging platforms such as WhatsApp and iMessage, which don't store the data.
Another Tweet by Snowden highlighted this issue: "What is #Allo? A Google app that records every message you ever send and makes it available to police upon request," he said.
Google responded in a statement: "We've given users transparency and control over their data in Google Allo. 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."
