Bigger issue: The published proof of concept of using “find friends” feature to find whether a phone number is registered on Snapchat or not, and if it is, then its associated username and location of the user. Two years back, some people reverse engineered WhatsApp’s api and found out a way to read (and modify) status of users on WhatsApp ( source), since Snapchat authenticates its users, the problem of modification is not an issue but the first issue still remains. Imagine this Adam has Eve’s phone number in his contact list but Eve does not Adam in her contact list, in that case, letting Adam know that Eve uses Snapchat or being able to pull her location is a bad idea.