The transportation firm stresses that its system won't be over-broad, as with the filtering systems at some workplaces, and will be limited only to sites that are almost unambiguously objectionable for public viewing. Other carriers, including American Airlines, are implementing similar policies, though in most cases are relying more on staff than on computer-controlled systems.

Delta's effort follows concerns from both passengers and stewards about some customers potentially viewing sites before a timely response is possible. Critics have charged that any censorship would affect free speech and personal use rights.