There are many stories of drugs being planted , yes ..the chances of it happening are slim however it certainly has happened .
Going from memory here , but there was a case in the 80s an Australian tourist arrived at there resort oppened their bag to find a rather large bag of white powder , they rang the Australian embassy immediately and were advised to get rid of the contents and the bag on a nearby beach and leave the country immediately , just in case the bag was to be " picked up " . I think this was in Thailand .
It certainly has happened , few with the profile of Schappelle . Its a different world in Asia , the blame is totally held with the one who claims possesion . For example if picked up in Thailand with " ya bah " tablets , the quantity held will be attributable to the individual unless the individual agrees to ring his/ her supplier and set up a " meeting " , this is how they catch the next person up the Tree .
On being simply Charged , the group is displayed in the Media ..on television , the whole bit . Still Rarely achieves the required result , just catches a few small players and gives them someone to display on the news .
Off the topic a bit , but certainly drugs have been " planted " on many individuals previously , just try not to be the " unlucky " one .