A viral social media challenge is raising major safety concerns.

A California man says social media might have saved his life, NBC News reports. Alex Griswold, 24, says that after he posted a lighthearted video on TikTok last month, viewers urged him to have the mole on his back checked out by a doctor. Two people who saw Griwold’s “what it’s like being married” video warned him that the mole looked...