I hate to introduce common sense into this fascinating discussion, but a) the almanac memo was not for public consumption. The AP got a copy somehow and they've been making hay with it for at least a couple of days. And b) one can logically assume that the FBI has noted that suspected terrorists have been reported to be carrying almanacs in several reports, thus warranting report of a pattern of behavior, like, say, having multiple ID cards or wearing a bomb belt.
I can't ever remember walking or driving around with an almanac, so I feel fairly certain this isn't going to affect me.
By the time this information filters down to the cop on the beat it will have been translated to "anyone with an almanac is a terrorist".