Frank is responsible for physical security at a large manufacturing plant. Employees all use a smartcard in order to open the front door and enter the facility. What is the MOST common way attackers would circumvent this system?

Tailgating involves simply following a legitimate user through the door once they have opened it, and it is a common means of exploiting a smartcard-based entry access system. It is simpler and usually easier than attempting to capture and clone a card. Phishing is unrelated to physical security. Although it is possible to generate a fake smartcard, it is a very uncommon attack. RFID spoofing can be accomplished but requires access to a valid RFID card and is relatively uncommon as well.