Okay, you can throw out those tin foil hats now…
“The thought screen helmet blocks telepathic communication between aliens and humans. An abductee who took voltage readings from a second helmet while wearing another one demonstrates that this communication is a form of electromagnetic energy. Aliens cannot immobilize people wearing thought screens nor can they control their minds or communicate with them using their telepathy. When aliens can’t communicate or control humans, they do not take them.”
(via Mind Control 101)