"Don't touch my bags if you please Mr. Customs Man"
A lot of airlines run promotions to reward travellers for choosing them and a lot of countries do tourism promotions that offer freebies of various sorts, but this is exceptional:
from the BBC
Cannabis blunder at Tokyo airport
An unwitting passenger arriving at Japan's Narita airport has received 142g of cannabis after a customs test went awry, officials say.
A customs officer hid a package of the banned substance in a side pocket of a randomly chosen suitcase in order to test airport security.
Sniffer dogs failed to detect the cannabis and the officer could not remember which bag he had put it in.
Anyone finding the package has been asked to contact customs officials. .
Just so you know, "sources" tell me that 142 grams of marijuana (that's about five ounces or "lids" as the kids call them) would mean a lump about the size of your average dictionary. Imagine finding that when you get home and unpack from your business trip or vacation.
I can't believe the dog couldn't find it - Given the amount, if the stuff is any good at all, they could probably just grab the first couple of people they see in tiedye down in Harajuku and let them sniff around for baggage area for ten minutes.
UPDATE: The stash has apparently been returned by the passenger who found it in his suitcase