Facebook announced this week the new "Secret Conversations" feature available in its Messenger mobile app similar to Google's Allo. Testing of "Secret Conversations" began this summer. According to Facebook, the feature ensures that only the users in a chat can see the conversations because of end-to-end encryption. Users can also select when messages expire. Facebook will benefit from the enhanced security it promotes that the feature provides and the comfort users feel using it.
But given what we know about the ease of access to supposedly secure information and using personal information generated from our use of social media, it is prudent to ask how secret is the information exchanged in "Secret Conversations." But, beyond concerns of how secure the messages themselves are from being subject to a hack, Facebook will probably use and provide the personal information in them for marketing purposes. Facebook also records and stores metadata on calls and messages that could reveal personal information, such as location of use, phone numbers, contacts etc.
Regardless of the level of privacy and security we expect in our social media communications, it is best to review evaluations from reliable sources about features like "Secret Conversations" and similar products that are available to meet our expectations. For example, Signal created by Open Whisper Systems has received positive reviews because it stores minimum information about its users.