We review programs and policies to prevent children from accessing alcohol marketing online. To update the literature, we present our recent studies that assess (i) in-built barriers to underage access to alcohol brand websites and (ii) commercial internet filters. Alcohol websites typically had poor filter systems for preventing entry of underage persons; only half of the sites required the user to provide a date of birth, and none had any means of preventing users from trying again. Even the most effective commercial internet filters allowed access to one-third of the sites we examined.