I think we'd all be surprised. My elderly parents are not tech geniuses, but between my brother (who is in IT) and I, we keep them robustly geared up with web safety software like adblockers and antivirus. And you go visit their friends in the over-55 community, and these people aren't savvy enough even so much as open an E-mail client, but somehow every one of them has at least some kind of blocker installed. This isn't the days of grandma isolated in her house on AOL. Everyone knows at least one tech wizard, and the wizards spread the gospel and help to install.
