Digital data mining spurs efforts to curb use without permission

Aleecia McDonald, a privacy researcher and Fellow at the Center for Internet and Society at Stanford Law School, says her work on users' understanding of digital behavior and privacy reveals a significant knowledge gap.

"They think they are protected by laws that don't exist," she said. Many people don't realize that third parties can track them across the Internet and are invisible to them. Others don't realize that ad content is influenced by what they write in emails.