A broad spectrum of “sunscreen truthers” on platforms like TikTok, Instagram, and Facebook have peddled the trope that sunscreen causes cancer for at least the last decade. These types of conspiracy theories have reached a fever pitch on social media since the pandemic. From vegan anti-vaxxers and bro-biohackers to MAHA and QAnon supporters, they all have two things in common: a case of chemophobia and a belief that sunscreen is the enemy.But digging beneath the underbelly of mainstream social media on extremist platforms infamous for minimal guardrails like Trump’s Truth Social (known for amplifying conspiracy theories) and 4Chan (notorious for being a breeding ground for hate and violence), the far right converges with the far left in a diagonalist (sharing the conviction that all power is conspiracy) intersection of sinister anti-sunscreen conspiracy theories.One in seven young adults (under 35) believe sunscreen is more harmful than the sun, according to a 2024 Orlando Health Cancer Institute survey. And studies show that the rise in skin cancer diagnoses in the past 30 years can largely be attributed to increased sun exposure, excessive sunbathing, and indoor tanning.Conspiracy theories, like the anti-sunscreen movement, “often originate on extremist social media platforms because they go completely under the radar in terms of law and policy discussions,” explained  Dr. Neil Johnson, Professor of Physics at George Washington University and Head of the Dynamic Online Networks Lab. Johnson and his team study how misinformation, extremist, and hate content proliferates on social media.