Scattering the spans more wouldn't do much... it's still pretty straightforward to gather the list of css classes used in the page and just piece together the innerText of their elements until you see a dictionary word (or even easier, a space).

In any case, there's always the impossible-to-defend-against attack: just hit PrintScreen on the keyboard, paste to MS-Paint and run the image through one of the many OCR websites that you can find via Google. Maybe even run it through MS-Word's autocorrect after that.