Their "core defense" for an end user is to notify the sender of a message if their post was screenshotted by using native screenshot detection/notification libr

Their "core defense" for an end user is to notify the sender of a message if their post was screenshotted by using native screenshot detection/notification libraries provided by the OS, combined with heuristics to try to prevent them from beeing hooked and bypassed. However, the binary level protection is only tangentially anti-screenshot insofar as it also blocks third-party 'scraper' apps. Fundamentally, it's about requiring use of the Snapchat app to access the Snapchat APIs, and as we know from the ongoing saga with other social networks like Twitter, this is ultimately about business control over posts (preventing spam-bots, scheduled clients, and so on) and at the end of the day, ad revenue.