In-flight filter for web access

IMAGINE YOU'RE trapped in midair in a cramped economy seat beside a fellow passenger who is surfing the internet - for porn.

When American, Delta and Southwest airlines bowed to customer demands for Wi-Fi internet access on flights, they did not envisage having to become net nannies. Nor did they expect to hear from crew and customers complaining of being exposed to mile-high porn.

When the problem first arose, earlier this month, American Airlines and Delta Air Lines responded by advising cabin crew to handle the issue themselves.

The role of monitoring passengers' internet use turned out to be a lot more difficult than serving food and drink, however. This week American and Delta announced that they will begin filtering their in-flight wireless services. Southwest Airlines intends to filter the internet, much as workplaces do, and Continental is going to give passengers e-mail and messaging capability only.

Virgin America will continue Virgin's international policy of not filtering the internet on flights.

Opponents of filtering say that many airline passengers read pornographic magazines, on sale in most airports.

Filtering may not even work, as filters can be circumvented or avoided by passengers who store pornography on their laptops. And if porn is blocked, some argue, will extreme violence be, too?