As a first guess, which the researchers themselves offer, the marker of internet savvy that they found was the frontal lobe processing, which is roughly that used in decision making, synthesis, and discrimination, is invoked. In other words, during internet search, savvy users constantly assessing the credibility of sources and validity of answers. This gives directly two principles which Google has used to dominate the market: authority, as encoded in page rank, and the swift checking of relevance and credibility, as helped by the short blurbs of relevant text, the back-links to similar pages or pages that link to it, and the quick viewing enabled by Google cache and 'view as html.' Anything further improving these processes would likely be a significant improvement in user experience.
It's a strength of the scientific method that one can offer a hypothesis without believing it. In any case, there are additional cognitive tests which one can use to examine the actual behavior from a different angle.
