It would look completely normal, except the letters and their symbols would be swapped. When I type "a" it would show as "z" and so on.
The scrambled webfont could be embedded, and the scramble could happen per font. An OCR or some reverse engineering could decipher the page, but as far as google indexing and all the modern "reading web content" is concerned, it would all read as random text.
Call it pagefucker or something. You'd do it to a page, and the result would be the modified text and the webfont to render it.
Just a thought!