A person’s voice can allow machine learning to guess a person’s age, gender, ethnicity, socioeconomic status and more, Wired reports. The voice recognition industry has grown into a $20 billion business. Users’ so-called “voiceprints” could be used for targeted advertising or the location where they are stored could be used by hackers to impersonate the user, such as robocall scams where criminals have a recording of a user saying “yes.” Privacy researchers are investigating methods such as anonymization or obfuscation to protect user voice data.