h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

So I asked a friend the following:
"My brother says he has to clean his computer now that one of our sisters has emailed him a link to some facebook thing. Is this true if he hasn't clicked said link?"

An answer came back:
"Tell him to run a virus scan to check. Probably fine if he didn't click any links."

I told my brother this but he responded in a way which made me decide to start this thread to hear my fellow researchers' advice and opinions about lethal cookies and other dangerous monsters on the net.

I'll start with this slightly different question:
"Is it true that Facebook is informed of the recipients adresse the moment I mail a Facebook-link to my brother? I've never heard of this exact thing before (but I've heard a lot of (other) conspiracies ...)"

Issues of the character that defy description I take as a challenge to my descriptive powers.

I feel rather swamped at the moment.

My advice for lethal cookies is that you don't eat them.

That's as far as I got myself, paulh, but thank you anyway

I've done a little research and found some interesting articles. Some are old and may not be up to date but may still contain some interesting data.
This is 10 years old:
https://www.cnet.com/news/five-hidden-dangers-of-facebook-q-a/
This was updated 3 June 2020:
https://www.computerhope.com/issues/ch000559.htm
And this is 3 years old:
https://www.cheatsheet.com/gear-style/reasons-why-you-should-stop-using-facebook.html/

But none of them answer my question: Is Facebook notified of my brother's email address if I send an email to him containing a link to something on Facebook?

Anyone! Family or friends, who send me emails with attachments or links - I automatically scan with antiviruseven thoughmy antivirus does it anyway

alsoccleaner is a good clearing of "cookies" etc after a internet session (there's a free version)

Cookies should be freshly baked and giving out aromas.