Apparently the learning curve for terrorists [let's face it, all terrorism is about power — not religion] is more of an arc. Quote:

Mexico Gangs Displaying Severed Heads

VILLA MADERO, Mexico — The drug lords at war in central Mexico are no longer content with simply killing their enemies. They are putting their severed heads on public display.

In Michoacan, the home state of President—elect Felipe Calderon, 17 heads have turned up this year, many with bloodstained notes like the one found in the highlands town of Tepalcatepec in August: "See. Hear. Shut Up. If you want to stay alive."

Joe Crowley   10 22 06