Your employer may know a lot more about you than you think.

The tone of your voice in a meeting. How often you’re away from your desk. How quickly you respond to emails. Where you roam in the office. What’s on your computer screen.

To be an employee of a large company in the U.S. now often means becoming a workforce data generator—from the first email sent from bed in the morning to the Wi-Fi hotspot used during lunch to the new business contact added before going home. Employers are parsing those interactions to learn who is influential, which teams are most productive and who is a flight risk.