Ask HN: Ahrefs, linkedin and a brief, minor freakout

For people who know nothing about web/seo, marketing like me, what is my relationship to ahrefs and linkedin, and is it anything I should think about beyond this post?

I discovered a 404 in my web logs, for a document with the name of a former employer in the filename, GET requested by the ahrefs bot.

When I looked closer, I saw my entire career in 404s, going back to 1975, including employers, industries, skills, etc.

It seems like a combination of my LinkedIn profile, and probably my listing in the address books of former colleagues who've given their address books to LinkedIn; one of the employers I found in my logs are not listed by name in my profile.

What does ahrefs, or LinkedIn or whatever actual client is doing this, get out of requesting docs that they must know will 404?

And what should I understand about my place in the automatic surveillance of the internet?

Anyone with better understanding of SEO or whatever this is, care to comment on what the world knows about me because of this, and what they do with it?