David Klepper | Associated Press

A growth industry is marketing unproven cures and treatments to conspiracy theorists and others who have grown distrustful of science and medicine. Experts who study such claims say they're on the increase, thanks to the internet, social media and skepticism about traditional health care.

Not long after the Ohio train derailment, pro-Russian voices on Twitter began spreading anti-U.S. propaganda about the incident. Researchers at Reset, the London-based nonprofit that uncovered the accounts, say they show how authoritarian governments are hijacking social media platforms operated by U.S. companies for the purpose of meddling in domestic debates.

In Pennsylvania, baseless allegations are spreading about delays in vote counting. Misinformation experts say it's not unusual for voting irregularities or delays to be spun into rumors.