Everything you say to your Echo will be sent to Amazon starting on March 28 - Ars Technica

Starting March 28, Amazon will no longer allow Echo users to process Alexa requests locally, forcing all voice recordings to be sent to Amazon’s cloud for processing. This change, intended to support Alexa+ and its voice recognition features, raises privacy concerns given Amazon’s history of mishandling voice recordings and employee access. Users face a choice: grant Amazon access to recordings or risk losing functionality like Voice ID.