The discovery of a USB memory stick containing classified NATO information in a library in Stockholm has prompted a meeting between the Swedish Military Intelligence and Security Service and foreign defence officials.

The Swedish Military Intelligence and Security Service is a division of the Swedish Armed Forces Central Command responsible for Sweden's military intelligence.

According to Swedish daily Aftonbladet, the stick contained material on NATO's ISAF peace-keeping force in Afghanistan, as well as an intelligence report on the attempted assassination of Lebanon's defense minister and the murder of Sri Lanka's foreign minister.

Colonel Bengt Sandström of the Swedish Military Intelligence and Security Service says this kind of carelessness is intolerable and can result in up to six months in prison.

It is unclear how the USB stick ended up in the library.

It isn't the first time the military has lost USB sticks with secret files. In 2006, a memory stick containing files on the Dutch military mission to Afghanistan was lost in a rented car. The documents also included information about the rules of engagement for Dutch troops in Afghanistan and the personal protection of Dutch Defense Minister Henk Kamp.

Also in 2006, the Dutch Defense Ministry reported the loss of another memory stick containing sensitive information about military intelligence agency MIVD.

If proper precautions are taken, the loss of a USB stick needn't mean the loss of information. A couple of companies already offer USB sticks with military-grade AES hardware-based encryption. Some can even self-destruct (internally) and erase everything on the drive using technology that physically overwrites every byte, making the data entirely unrecoverable. ®