As the content scripts guide notes, content scripts don't see changes made to the DOM by scripts loaded by web Pages. This means that, for example, if a web Page loads a library like jQuery, content scripts won't be able to use it, and have to load their own copy. Conversely, scripts loaded by web Pages can't see changes made by content scripts....scripts running in arbitrary web pages are hostile code whose aim is...scripts and scripts loaded by web pages is intended to make it more...