> Lets code dynamically change things that other code depends on. Including behavior in built-in object prototypes. Not exactly uncommon for languages that fea

> Lets code dynamically change things that other code depends on. Including behavior in built-in object prototypes. Not exactly uncommon for languages that feature reflection. Heck the win32 api allows you to hook and intercept function calls. So do plenty of other native C and C++ APIs. It is a powerful feature that allows for a lot of functionality, including extending out libraries and fixing bugs in SDKs that you'd otherwise have to wait an entire release cycle for, or that may never get fixed. (And release cycles used to be years long!)