I believe the technology used to target individuals was likely obtained from the Nazis after WWII, and probably used by them during the war. MKULTRA was said to be the CIA's "mind control" program, which is thought to have begun in the early 1950s, but the ULTRA designation indicates it is probably a carry over from WWII as ULTRA was the designation among the Allies for ultra (highest level) secret intelligence (particularly signals intelligence). I believe this technology, which appears to be able to do many different things besides V2K, could have been a reason the Nazis felt they could do what they did - do something so outrageous both in terms of its atrociousness and its scope (essentially taking on the world).
I also think that it would be unreasonable to assume the the USA / CIA were / are the only ones who obtained / have the technology. At least the other 5 "eyes" would have it, and probably Russia and China too. This is why I believe people have been targeted NOT by the CIA, but by a ANOTHER GOVERNMENT seeking to attack the "human capital" of the USA and other countries and get people to blame the CIA / US Government due to the publicity of MKULTRA. This seeks to reduce the power of the US government. And if you think about it, it doesn't make a lot of sense that the CIA / US Government would want to harass people, particularly it's own citizens in this way, such that everyone is accusing them of illegal acts. This is not in their best interest. And I would argue it isn't likely corruption, money making, etc either, because you can't make money if your country collapses, or if the tax paying human capital is being attacked such that they are less productive or worse.
This technology could have been this horrible thing the Allies discovered after the war that might be difficult to defend or protect against since it might use radio waves or microwaves or even sound waves. And I believe it must be difficult to trace the origins of the attacks. They must be able to use the technology covertly (perhaps shielding a specific area and sending wired information to an electromagnetic wave transmitter). Something like Pine Gap in Australia has underground facilities with several above ground antennas. Plus Americans are barred from the Australian Cryptographic Room, and Australians are officially barred from the National Cryptographic Room (USA). With no way to avoid it, the countries involved may have had to watch, wait and hope that no one would use it negatively, but someone did. This may be just one reason why the CIA / US government hasn't or can't acknowledge it, and also hasn't been able to do anything about it thus far. How do you tell the world there is a weapon that you can't escape?
It is clear to me we are under attack. For example, I believe the mass shootings / bombings are often induced by harassment using this technology. Many of these people have said they heard voices, and seemed to experience similar things that other targeted individuals have said. This is an attack by a foreign government to sow chaos and fear, and they use various other tactics to achieve this as well. In addition, they are likely attacking us in ways that hurt us economically. It appears the technology makes it easy to track and attack individuals, even without them being aware of it. I believe it can do so many things, including things like mimic illness which makes people seek medical care. Done on a large scale over time, this can increase health care costs in an unsustainable way. And there is so much more.
Addionally, I found this from the Naval Postgraduate school that demonstrates a technology that makes it theoretically possible to put sounds / voices in someone's head that can't be heard by others. Again, I don't believe this would be coming from the US government - it (or something like it) could be transmitted from anywhere via satellite (or even some other method) that is highly sophisticated and computer aided. And I doubt the US would be demonstrating it if they were using it negatively against anyone, particularly it's own citizens.