In the second of two episodes exploring anti-vaccine misinformation online, Renee DiResta of the Stanford Internet Observatory explains why the Internet is so good at spreading bad information, and what big tech platforms are starting to do about it. Listen to the prior episode to hear more from Renee, and the story of pediatrician Nicole Baldwin, whose pro-vaccine TikTok video made her the target of harassment and intimidation from anti-vaccine activists online. You can see Dr. Baldwin's original TikTok here. Renee DiResta has written about how some anti-vaccine proponents harass, intimidate, and spread misinformation online here and here. Email the show at shortwave@npr.org.