Actually the page can only be notified when you type a certain message in the address bar and it's limited to ONE message in a browser window so it can't try to watch for a list of strings. When there is a match a new tab will open up so you would notice this if it was being used. This feature was intended for an easter egg so the page could say, for example, "let me know when the user types 'I love Firefox' in the address bar" and then open a tab with an easter egg page. Also note that all tour functionality only applies when the tour tab is selected. Hopefully this clarifies that the page can't really spy on the address bar.

The word processor can spay what you are typing. Also this web page can spy the comment I am typing. Including the stuff I deleted.

Please before it say "it spies", show us what it captured and sent to third-parties (ie not YOU).