What the Organization wants to root out is the double agent.
Who is the most likely candidate? It is the person with the target on their back from the following behaviors.
1.Spotty meeting attendance
2.Low field service stats
3.Murmurers who "question" things innocently.
4.Persons with unbelieving members in the household.
5.Brothers (or sisters) who make sharp replies to questions that bring in "outside" information not in the publications.
6.Members who seem to be more aware than average about worldwide problems in the Organization. (i.e. sexual abuse, U.N. scandal, lawsuits, etc.)
7.JW's who avoid giving yes or no answers to loyalty questions.
Can there be a Kingdom Hall without such people? Hardly.
From what I've heard (second hand from active JWs) the most likely candidate for apostacy are actually Elders fed up with pressures and policy flip flops!
They get themselves disfellowshipped in a blaze of glory. They bad mouth the Society for a while and then, slink back with their tail between their legs begging for forgiveness after they have purged themselves of built up angers.
If there is a STING operation being planned it will work.
It is called "Disinformation". Variations of sensitive details will be spread in different areas. The detail that gets leaked will identify which area it came from. That will identify which Kingdom Hall houses the offender. From there, by direct questionings the guilty party will quickly be rooted out.
Once you are pissed off at the Org it is almost impossible to proclaim loyalty when directly asked without hedging and dodging.
Such a plan can work.