Parents are struggling with their teens' use of social media.

Social media companies like Facebook and Instagram are aware ... and they're starting to set age limits and standards ... but the U.S. surgeon general says they should do more

The age in question here is 13-years-old -- that's the age at which Facebook and Instagram allow young teenagers to have their own accounts, but Dr. Vivek Murthy thinks 13 is still too young.

Karen North directs the Annenberg Program on Online Communities at USC and joins the KNX afternoon news.