This article was written by Erin Carson in Cnet:

The accounts of TikTokers between the ages of 13 and 15 will default to private, TikTok said in a blog post Wednesday. 

The change is part of several updates to the social network's privacy policies aimed at its younger users. "As young people start their digital journey, we believe it's important to provide them with age-appropriate privacy settings and controls," the post said. 

In addition, only friends or no one at all will be able to comment on videos -- TikTok is removing the option for everyone to comment. Those under 16 won't be able to use the duet or stitch features (both effectively let you incorporate other TikToks in your own), and those 16 and 17 will only be able to use them with friends. 

Other changes include restricting direct messaging to accounts held by those 16 and older, and only permitting the downloading of videos also made by those 16 and older.