Pop-up bollards have been around since the 1100s, says James M. Atkinson, president and senior engineer at Granite Island Group, a security consultancy in Gloucester, Mass., calls “avocado” security. “A clever new toy doesn’t make you more secure,” says Atkinson. Avocado security is better, though not foolproof, says Atkinson, who has tied bomb-tipped broomsticks to a pickup truck, blown up a bollard and then driven his truck to the target area.”]
Source: https://www.csoonline.com/article/2122896/bollards.html