I think the crux of it is that people don't expect Snapchats to become public. They expect them to be more like text messages where there's an expectation of p

I think the crux of it is that people don't expect Snapchats to become public. They expect them to be more like text messages where there's an expectation of privacy. When a user posts on Facebook, there's an expectation that the content is out there for people to see. If you post a public video on YouTube, you expect people to see it. If you uploaded a video on YouTube, there's an expectation that the local news might show it. But no one expects the local news to show an embarrassing Snapchat you sent to your friends. But even Facebook's TOS is a lot kinder. "This IP License ends when you delete your IP content or your account unless your content has been shared with others, and they have not deleted it." Most people don't re-share photos. They comment and tag them, but if you delete the photo, Facebook's license to it ends. They can't then give that photo to a news paper because they no longer have a license to it. Similarly, YouTube's TOS has a similar provision. "The above licenses granted by you in video Content you submit to the Service terminate within a commercially reasonable time after you remove or delete your videos from the Service." If you delete content from YouTube, they're license to the content terminates within a commercially reasonable time after you delete it. So, both Facebook and YouTube let you terminate the content license even though there's a better assumption about the content being public. People have been using Snapchat assuming they can't be made public if they ran for Congress or something. In fact, while people might have seen stupid YouTube or Facebook posts from them, if they only retained a bookmark and didn't save a copy, they could delete those embarrassing moments before their run and terminate that license. In fact, because receiving users see Snapchat as ephemeral, they're much more likely to save a copy of the image using a screenshot than Facebook users are. Facebook/YouTube users often assume that the content they see will be there in perpetuity.