I'm not saying it's at every AD but I've heard more than one report that they're there.

I know there's something in place in Canada and the US as any shipment of Rolexes caught by Customs between these two countries are pretty much immediately confiscated, even if you're stating it's for "repair" purposes.

As for getting in trouble, at YVR, I've personally seen (and was the recipient) of wandering Customs agents demanding to look through my "stuff" on a returning Asian flight (from NRT of all places!). Upon showing my watch, they demanded to see my record of duties paid, or else it'd be confiscated on the spot.

Luckily, I always keep a photocopy of it with me when I travel.