This is basically what I'm worried about.
My mom does things like share USB drives with her writing group who are all the same age because they're all working on their own novels or art-series where the files are larger than 25 MBs, and not everyone has Google Drive enabled or uses gmail.
My dad does not do any of that stuff and he knows not to click on weird things. He just goes on business trips to China.
Adblock plus and java-disable is probably the way to go, I'm just pretty sure that at some point they'll reverse the setting because some website they use told them to and never turn it back on.