It may not be clear, but the main use case for this app is not to harm someone, but to aid in development.
Perhaps you're making a game and want to pause it or show wireframes when toggling the inspector.
Or perhaps you're a designer and you want to show a grid layout whenever you're inspecting elements.
Or perhaps you want to make it so that when someone tries to inspect a DOM element, the element turns into a youtube video of Rick Astley singing "Never Gonna Give You Up." --Just sayin...
That may have been your aim and while there is a great potential good, there's also a great potential for evil. You've opened pandora's box and now we'll see how it plays out. My guess is that we're going to see a lot of misguided website abuse this until the Chrome team has to patch it so websites can't know its state.