So I saw this really cool google plugin called vimium, it allows users to press a mod key ("f") and then easily access any hyperlinks that are present on the current page by providing visible shortcuts (e.g., "A") as tooltips on the hyperlinks, and on pressing these shortcuts (e.g., "A") you can go to the hyperlink associated with "A". Microsoft has a similar feature in excel and word. And on researching a bit I found this patent.

Is what vimium is doing illegal? Can an idea like this even be patented? It's not a core technology, they are just trying to show shortcuts in a box. Can someone please explain what this link says, as I'm not sure if this idea is actually patented or just filed for a patent.