Slate's Bizbox
explainer: Answers to your questions about the news.

What Makes Laptops So Dangerous?Why they get special attention at the airport.

By Daniel Engber
Posted Tuesday, Nov. 22, 2005, at 6:43 PM ET

Download the MP3 audio version of this story here. The Explainer now has its own free daily podcast; click here to learn more.

A closer look at computers. Click on image to enlarge.

Almost 22 million people are expected to travel on U.S. airlines during the Thanksgiving holiday period, and wait times at the airport may increase as a result. As usual, airlines are telling passengers they can save time if they remove laptop computers from their carry-on baggage before they get to security checkpoints. Why do computers get so much attention?

In theory, a laptop might contain a bomb or hide a weapon. The Transportation Security Administration requires that all laptops be taken out of carry-on bags and passed through scanners on their own. The rule allows screeners to get an unimpeded look at each computer, which might help them discern whether it contains hidden explosives. And removing a laptop also makes it easier for screeners to see whatever else is in the bag. Computers can be large and dense enough to conceal parts of a suitcase in an X-ray image. (A knife, for example, might slip through a scanner if it were tucked underneath a heavy laptop.)

No one worried too much about electronic devices in carry-on baggage until the 1989 bombing of Pan Am Flight 103 over Lockerbie, Scotland. The device that destroyed that plane—and killed 270 people—turned out to have been hidden inside a boom box.

After this incident, Congress briefly considered banning electronic devices in the cabin. Instead, the FAA asked airlines and airports to exercise more scrutiny over cell phones, radios, alarm clocks, computers, and other electronics. As a result, many travelers were asked to turn on their laptop computers at screening checkpoints, to prove that they functioned normally. (Some airports made powering up a computer mandatory; others required it only for travelers who were afraid to send their computers through the X-ray machine.) Laptops with dead batteries were sometimes taken to a special room and plugged in. By 1993, the process had become enough of a hassle that one company released a program called "Airport Shut Down"; it put your computer to sleep—rather than turning it off completely—in advance of the screening.

Security experts argued that these procedures were a waste of time, since you could easily hide a bomb inside a functioning computer. (Explosives could be packed into disk drives or internal cavities for additional hardware.) By the late '90s the practice had mostly disappeared, but the exact rules for screening laptops—and whether they needed to be taken out of the carry-on baggage—seemed to vary from place to place up until 9/11.

Since the end of 2001, the removal of laptops from carry-on baggage has been standard practice at U.S. airports. Initially, this practice led to a dramatic increase in reports of lost property, as passengers forgot their computers at security checkpoints. (In early 2002, Denver officials resorted to posting "Got laptop?" signs around the airport.)

Help the Explainer: Do you have to take your laptop out at airports in other countries? The Explainer couldn't get a consistent answer to this question from American security experts or international aviation organizations. What's your experience? Write down where you were and whether you had to remove your laptop from your carry-on luggage—and send it to .

Got a question about today's news? Ask the Explainer.

Explainer thanks Doug Laird of Laird & Associates, Doug Lavin of the International Air Transport Association, and Billie Vincent of Aersospace Services International. Thanks also to reader Justin Drake for sending in the question.

Print This ArticlePRINTDiscuss this in The FrayDISCUSSEmail to a FriendE-MAIL
Share on FacebookPost to MySpace!Share with MixxDigg ThisShare with RedditShare with del.icio.usShare with FurlShare with Ma.gnolia.comShare with SphereShare with Stumble Upon
Daniel Engber is an associate editor at Slate. He can be reached at .
Photograph of airport security station by Justin Sullivan/Getty Images.
Join the Fray: our reader discussion forum
What did you think of this article?
POST A MESSAGE | READ MESSAGES
Washington Post
The Washington Post
OPINIONS
Topic A: Obama's Speech
| Pundits and diplomats respond.
Robinson: Sunshine in BerlinToles: Obama the UniterTelnaes: Meanwhile, McCain
PLUS » Stumped: Bring Back Bill Clinton