Mental health experts are troubled that a "delusional" belief system — which leads believers to fear they are constantly being watched or harassed and has even been linked to mass shootings — is now advertised on Vancouver's public transit system.
The ads are about beliefs called "organized stalking" or "gang stalking". It holds that conspirators, perhaps dozens of them, are stalking and harassing "targeted individuals" by damaging their personal property in subtle ways or spreading rumours about them.
Some targeted individuals also believe they are victims of "electronic assaults": torture via weapons from sci-fi movies like microwave rays and body-implanted microchips often with mind-control powers.
However, researchers agree these beliefs are usually caused by some sort of mental disorder.
"I have not seen any evidence, good, hard evidence, to suggest that this is an actual thing that happens to people," said Christine Sarteschi, a criminology and social work professor at Chatham University in Pittsburgh, who has researched organized stalking.
Sarteschi said organized stalking beliefs thrive in internet echo chambers on websites and social media that reinforce beliefs and dissuade each other from getting mental heath treatment.
Freedom For Targeted Individuals did not reply to an interview request from CBC. The group's website also claims it has bought, or soon will buy, ads in Los Angeles, Phoenix and other cities.
TransLink, in an email, said it had no plans to take down the billboards which it believes conforms to advertising standards.
"As per a Supreme Court of Canada ruling determining TransLink is a public agency, it is bound to respect the Canadian Charter of Rights and Freedoms and accept advocacy advertising like this," a spokesperson wrote.
Dr. David James, a psychiatrist in London, England, who co-wrote what is believed to be the first academic research on organized stalking in 2015, said he was "saddened and somewhat concerned" to see these ads.
"The appearance of such adverts is likely to reinforce the delusional beliefs of some mentally ill people and discourage them from accepting treatment which will improve their mental health," James wrote in an email.
"It will also encourage them to assume a paranoid interpretation of events around them ... and may lead them to angrily challenge entirely innocent members of the public.
"Such behaviours have attendant risks."
In James' study, two senior clinicians examined text solicited from 128 targeted individuals. In all cases, the clinicians believed there was a "high likelihood" all were delusional, likely suffering from paranoid psychoses like schizophrenia and delusional disorder.
The research found compared to victims of conventional stalking — where a single culprit harasses or follows a victim — group stalking believers were more likely to be fearful, move homes or change jobs, lose bonds to family and friends and even carry a weapon.
Sarteschi's research looked at four cases where four mass shooters left behind clues suggesting organized stalking beliefs played a large part in their crimes.
"When people have delusions, they really believe that it's happening. It's as real as rain to them," Sarteschi explained.
"And for some unstable people, who might fear that something's going to happen to them, that they might need to act to stop someone from hurting them, they might then engage in extreme violence."
'A life of its own'
David LaPorte, a psychology professor at Indiana University of Pennsylvania and clinical psychologist with 30 years experience, expressed concern that the targeted individual movement could make it more difficult to get paranoid people into treatment since they are already reluctant to seek help.
"No one likes to be told they're crazy," LaPorte said. "No one's out there looking for alternative explanations. They're looking for evidence that it's the government using satellites against them."
The thought of these groups buying advertisements on Vancouver's public transit system and elsewhere troubles him.
He says there is evidence that the more a person is exposed to an idea, online or on the street, the more likely they are to believe it.
"This is going to start taking on a life of it's own," he warned. "You just never know where something like this is going to go."