Google Hangouts doesnt implement end-to-end encryption, when users message or talk with someone on Hangoutsis exposing to Government Wiretapping. Apple has always denied any involvement in the surveillance programs operated by the US Government. Despite the market is offering solutions that promise to be NSA-surveillance proof the majority of people still use messaging apps like iMessage or Google Hangout. Google confirmed to Motherboard that Hangouts does not use end to-end encrypted.”]
Source: https://securityaffairs.co/wordpress/36749/intelligence/google-hangouts-wiretapping.html