"Keep it legal: Don't use Snapchat for any illegal shenanigans and if you're under 18 or are Snapping with someone who might be: keep your clothes on!
What not to Snap:
Pornography
Nudity or sexually suggestive content involving minors (people under the age of 18)
Minors engaged in activities that are physically dangerous and harmful
Invasions of privacy
Threats
Harassment or Bullying
Impersonation
Self-Harm"
The move makes obvious sense. The app first gained popularity from people looking to exchange nudes that self destructed in seconds, but has since evolved into much more. In many states, as well, having a photo of a person under 18 is technically considered child pornography, even if you yourself are under the age of 18.
Source:
Fusion