For years, traffickers have posed as translators to infiltrate the country's holding places for Rohingya boatpeople, either in family shelters or detention centres.
With Thai officials unable to converse with the boatpeople, it was a simple matter for someone who speaks the Rohingya language to offer help.
At a family shelter, for instance, the Rohingya ''translator'' would tell the women and children: ''Hop over the shelter fence at 1am and I will have three pickups ready to take you to the border to be reunited with your husbands and fathers.''
Thai officials would be within earshot but unable to understand, failing to realise that human trafficking was taking place right under their noses.
Now that the 14 trusted permanent residents in Thailand have been sanctioned by the Ministry of Social Development and Human Security, the ruse should no longer succeed.
The appointment of the official translators is the latest sign that Thailand is now, at long last, taking serious practical action to end human trafficking.
More arrests of senior officials are likely within weeks because of unexplained wealth, Phuketwan has been assured by one usually reliable and well-placed source.
Some of them could be military officers, we have been told.
A complete change in approach appears to be underway from the days of no enforcement when people were bought and sold with ease all along Thailand's Andaman coast.
In his weekly televised speech last Friday, Prime Minister Prayuth Chan-o-cha even made the point that the treatment of boatpeople throughout the region should become an issue for Asean.
Only with Asean's active involvement can the ethnic cleansing of Rohingya within Burma (Myanmar) be halted.
In the past, the Asean nations have always avoided interfering in the internal affairs of member-nations.
The shocking treatment of the Rohingya in Rakhine state inside Burma is no longer ''an internal affair.''
It's a crime against humanity that will fester and become genocide unless Thailand and other neighbors take action to force Burma's reluctant government to promote religious tolerance and understanding.
Since 2009, Thailand's ''help on'' policy has actively assisted the Burmese government in expunging the wrongly-reviled Rohingya Muslims.
Instead of telling its neighbor to behave with normal standards of human decency, Thailand effectively aided and abetted an attempted extermination.
Villages along the Andaman coast - both north and south of the holiday island of Phuket - came to thrive on a cottage industry, a trade in people that grew more important to some as a source of income than tourism.
And all the time, there was next to no enforcement. Under the ''help on'' policy, boatpeople were given food and water and other assistance - provided they did not land in Thailand.
Because there were few interceptions at sea and little enforcement, traffickers opened up pipelines for the people trade that ran from secret coastal camps hundreds of kilometres south to the jungle along the Thai-Malaysia border.
Brutality increased. Deaths mounted. Trafficking expanded from Burma to Bangladesh, where young men especially were lured onto boats with promises of better jobs just a sea voyage away.
Once on board, unwilling travellers or not, the traffickers' passengers became ransom victims, ripe for extortion of large sums from family or friends.
The monsoon season and a crackdown on trafficking brought the shocking trade to an end earlier this year, but permanent answers have yet to be proposed and pursued.
All of the answers lie inside Burma, but it is the responsibility now of Thailand and Asean to make sure the boats stop.
The only certain way to do that is to insist Burma speedily develops the religious tolerance it needs to take its rightful place among the world's developing democracies.
WATCH Journey into Hell, by Four Corners
From Burma through Thailand, an award-winning current affairs team traces official complicity in the brutal treatment of the Rohingya and Phuketwan's part in its exposure.
WATCH How Trafficking Works
Phuketwan Investigative reporter Chutima Sidasathian says of traficking in 2014: ''It's worse and worse, day by day. Nobody cares''.
LISTEN The Rohingya Solution
A tragedy almost beyond words has been unfolding in Thailand, where a human smuggling network is thriving with the full knowledge of some corrupt law enforcement officers. Alan Morison of Phuketwan talks to Australia's AM program.