"Put the book down and step away slowly!"

Okay, this is getting seriously weird.

WASHINGTON (AP, December 29) - The FBI is warning police nationwide to be alert for people carrying almanacs, cautioning that the popular reference books covering everything from abbreviations to weather trends could be used for terrorist planning.

In a bulletin sent Christmas Eve to about 18,000 police organizations, the FBI said terrorists may use almanacs "to assist with target selection and pre-operational planning."

It urged officers to watch during searches, traffic stops and other investigations for anyone carrying almanacs, especially if the books are annotated in suspicious ways.

"The practice of researching potential targets is consistent with known methods of al-Qaida and other terrorist organizations that seek to maximize the likelihood of operational success through careful planning," the FBI wrote.

Coming in the next bulletin: The dangers of AAA road maps.