The Maria Duval scam appears to have used something similar. It also appears to have used a form of pre-targeting of its victims, as many of them were in the first stages of dementia or Alzheimer's disease.
They probably received something to induce the memory at some point, and then a metal token that was connected to the specific memory. At that point they believed the person they were dealing with was like a family member and an old time friend. This explains all the odd correspondence they sent back and forth, describing Maria in glowing terms.
There were posters they were asked to focus on, and coins also that were used to insure that the people stayed in the right position so that the payment was received by the correct person on the other side, and not by another. The poster featuring sets of alternating red and blue circles has no other real use.
Then afterward, someone collected the money, and part of this apparatus has been uncovered (a company was doing it and illegally transporting the money by plane.) The money then went around to the people who started the scam (Chinese Vampire Billionaire, some people in India.)
They then removed the initial memory kick from the object, if they even bothered with that, and the victims began to have problems remembering what exactly happened. They could also put in a batch of really negative memories like they did with me, as a form of blackmail to keep them silent.
I can't fins a pic of the red and blue target poster, but this is the kind of thing they did:
Future fraud: cons thousands with the promise of happiness | FOX6Now.com
Nice use of red and blue here:
The Light Keeper: Mail from Maria Duval -- or Best Laugh of the Week
This might be known as "the stinger" scam, because it corresponds to that "40 days of pain" people suffer in the bible at the hands of devils that are like scorpions. They love using that kind of stuff, and say right in their material, "study the coin for 40 days and you will reach enlightenment."
The problems governments had with stopping the scam are a result of it being able to move around and avoid detection, or to change and hide itself instantly. The FBI can't figure this out, and if they have they aren't saying too much about it.