The wiretapping is a typical of the old school, while the brain reading is the most advanced, which should be employed by several intelligence organizations.
The CIA and Japanese police intelligence have this capability, which also means members of UN Security Council and Five Eyes should have it as well. I assume Germany, Israel, India and Korea should have this technology, but I have no idea how many others can employ it.
The brain reading is one of the electromagnetic wave manipulation technologies, but the wavelength is different from other radiowave maneuvers. It uses a radar, not an ordinary ultra-long wave, though the radar can be remodified for construing its meaning. There are many mixed elements of technology, hence it is more difficult to achieve than just an electromagnetic manipulation.
This reading technology makes the assetization unnecessary, as the spy can take information directly out of the brain, even for a quite critical intel.
On the other hand, it is nearly impossible directly access to the human memory from the outside, hence it is not certain that the spy can obtain a necessary information. If they would like to get it, they need to use a truth drug, which is only possible under a confinement of the subject, not an easy mission.
When the spy employs this brain reading with an ordinary electromagnetic wave manipulation, they can get more detailed intel. The reading is just capable to read what the subject thinks, while the manipulation is just capable of affecting a thought and emotion of the subject.
Mixing them up, the intelligence can communicate with the subject interactively, to send a question by the ultra-long wave and to receive its answer by the radar. It requires a time to conduct this operation secretively to the subject, but there is a large possibility that the intelligence can get an information which they would like to gain without notice.
This two-way electromagnetic operation has a sizable impact on the subject, though it is not always that the spy controls a decision making of the subject. As a result, the assetization is still conducted to acquire a critical person as their asset. The brain reading is, contrarily, to be used secretively to take an intel from their target in a long run.
As far as correctly understanding these technologies, the nullification should be developed as well. I also have had several ideas to counter, though my environment is not enough to construct those devices, while there should be some for the nullification in practice already.