Recently noted Chicago's knife laws in this forum re: limiting a carry knife to 2 ½ " blade length (did I read this right?....anyway, assuming I did). I've often passed through Ohare and haven't given much of a thought to my SAK or whatever "legal" blade I had tucked in my carryon. Neither has security there. So, do I now face a potential problem when "just passing through" if one of these blades is over 2 ½"?