I'd have thought there was a bright line between people like my parents who use the ubiquitous "share this link" site features, and people like me who send mess

I'd have thought there was a bright line between people like my parents who use the ubiquitous "share this link" site features, and people like me who send messages with links and excerpts tailored to the recipient. If I'm right, you're an edgier edge case than Mr. Gruber.