tedster - 1:54 am on May 23, 2012 (gmt 0)
All the divs are served at one time (with gzipped text, that's not a speed issue) so the bots reads ALL the content every time but the users get to pick and choose what's visible to them.
A finer point can be a script thjat captures referrer search terms from any SE traffic and then ensures that those divs load originally as visible, with each occurrence of the search terms highlighted in some color that works with the page's look and feel.
Far from being an SEO risk for this particular site, it has become their bread-and-butter. It's been in place since 2003 and always been an asset. It really helps the end user!