Jonah – Since you and many others are making fun of the almanac warning (including some silly people – Olberman – and some not silly people – Volokh), I have to put in a bit of a defense.
First of all, it’s misleading to suggest that cops are now supposed to look around for guys walking down the street carrying almanacs. The idea is that officers who may have already stopped someone in their car or are searching a residence, etc., to keep an eye out for an almanac if there may be other indicia of terrorist activity. So if a guy is stopped for speeding, has sketchy id, is on a visa from Saudi Arabia, and has an almanac, that’s something to be aware of. Or say a hotel maid finds some arabic notes left in a room, freaks and calls the cops. Maybe it’s innocent, but what if they also find an almanac? Rather like if he had a map of Las Vegas and a flight manual – not nefarious in themselves, or even necessarily together, but worth investigating.
A bit more subtly, the alert can also help to provide “reasonable suspicion” or “probable cause” to stop and/or search someone. I currently clerk for a federal judge, and one factor (the factor, really) in determining whether a search or seizure is legitimate is whether the suspect did anything to arouse probable cause that he was involved in a crime.
By telling officers that some terrorists may be using almanacs, the government is giving them an extra fact backing up their claim of probable cause to arrest someone who may not have given any other reason to arrest them. (Say our guy from Saudi Arabia above is pulled over for running a red light, but has legit id. The officer would have no reason to arrest him – he could give a ticket for the traffic violation, but not arrest – so he’d be set free. But now, if the guy has an almanac in the seat next to him, perhaps he can be detained, or at least questioned further. I’m not saying the police would necessarily win this case, but at least it would give them a chance to check things out.