A year or so ago we were landing in PER from MEL (maybe SIN, I can't remember) and, although the flight appeared uneventful to me, the Capt made an announcement as we approached the gate asking everyone to "stay seated for a few minutes". When the door was opened two AFP (Australian Federal Police) officers and a K-9 (a proper one, not a quarantine Beagle) entered the jet, went to the back of Y somewhere (I was in the front of Y) and came off the plane with a "hippie" looking guy in handcuffs. Except for the fact that the guy looked somewhat feral he didn't appear to be intoxicated or resisting in any way. I never did hear what had happened but, yeah I'm probably profiling or stereotyping, but my guess is that he probably had drugs on him that one of the other pax found out about and the K-9 was used to establish PC for his arrest.