I have a project (in my rather long project backlog) that involves hooking JS APIs to download youtube videos. I'm worried that if my extension (or a similar extension) gained enough popularity, youtube would start inspecting the relevant JS objects to see if they'd been replaced with proxy instances.
Aside from playing a hooking/patching game of cat and mouse, I don't think this is fully solvable without modifying the browser engine itself - then you can hook things in a way that's completely transparent to the JS in webpages.
Aside from playing a hooking/patching game of cat and mouse, I don't think this is fully solvable without modifying the browser engine itself - then you can hook things in a way that's completely transparent to the JS in webpages.