But no, he wasn't thinking along those lines, even though he identified one of the brain's primary functions as to protect us. He was referring to the way the brain receives information and puts it in virtual drawers, or what he called "buckets." We categorize the world and evaluate things based on whether they might be harmful or beneficial to us. Categorizing helps us learn associatively: New Object X is similar to Familiar Object Y, and Y is good, some X is most likely good too. This is also an aspect of the brain's protective function.
The downside, as I observe it, is that our brave new Web-Wide World exposes us to more stimuli and information than our brains can properly process. Too much of the information is inaccurate or incomplete, and we need Snopes or some equivalent as a third-party bullshit detector, but that's a side-issue. If our brains do not have time to figure out which bucket something belongs in, we tend to winnow down the number of buckets we use.
Too often, that number of buckets is reduced to two. We stuff information haphazardly into buckets labeled "harmful" and "beneficial." Perhaps later we'll devote the time to examine something and categorize it appropriately, but perhaps we won't.