[1]https://news.yahoo.com/many-200-americans-now-reported-083000770.html

Almost half of those reporting symptoms are linked to the CIA, say officials, wi
th possible cases in Berlin and Vienna and on every continent but Antarctica.
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Jim Bell's comment follows.

Given how easy it should be to do an audio or radio/microwave spectrum analysis,
 using a SDR and smartphone, I'm surprised this is still so mysterious.

References

   1. https://news.yahoo.com/many-200-americans-now-reported-083000770.html