Google Allo was recently released to mixed reviews, but it's in the news lately for all the wrong reasons.

Now, NSA whistleblower Edward Snowden tweeted a warning about people using Google Allo considering the news that it might be used for surveillance purposes.

The tweet reads, "Free for download today: Google Mail, Google Maps, and Google Surveillance. That's #Allo. Don't use Allo."

According to the news article from The Verge, Google Allow will save all messages sent on non-incognito mode by default. And they will remain stored up until the user will manually erase them. That means Google will get access to the full conversation history used by the app.

However, people can bypass this issue by going incognito. That is if they know about the privacy issue in the first place.

But why does Google persists in doing this despite the criticisms about the privacy issues?

Apparently, storing the messages will buttress Google Allo's feature on the smart reply. Like most AI, the feature needs data in order to machine-learn responses and the search giant seems to be prioritizing the smart reply over privacy issues.

Meanwhile, in related news, Computer World said that Apple's iMessage app is still better than Google Allo, especially since in terms of functionality, there's not a world's difference compared to the current Hangouts.

It said that the iMessage has a lot of goodies for users to play with like the special effects and the "invisible ink." Unlike Google Allo, the Apple messaging service is also touted to be more secure due to the strong encryption on messages sent via the service.