Glossary
Tailgating
Tailgating is following an authorized person through a badge-controlled door while it's held open for them, without presenting any credential of one's own. The digital access-control system worked exactly as designed — it correctly verified the person who badged in — and the bypass happens entirely in the physical world, through simple social behavior: most people hold a door for whoever's right behind them, and most people who follow through an open door aren't challenged about it.
No amount of hardening the digital badge system addresses this, because the failure isn't in the system at all — it's in the physical behavior around it. Closing this gap generally requires physical controls like mantraps or turnstiles that make following someone through genuinely difficult, or a workplace norm of actually challenging unfamiliar people who tailgate, rather than any improvement to the badge-reading technology itself.