If your social media profile lists your employer (such as on LinkedIn), a single "check-in" or a photo of your dinner at a foreign resort instantly connects the dots for an adversary. It tells them where you work, where you are right now, and most importantly that your home in the U.S. is currently empty.

1. Scope Note This National Intelligence Estimate (NIE) provides a comprehensive and in-depth assessment of the long-term threat posed by...