I am surprised to find so little information about what I would consider a serious breach of privacy and security.
ubuntu-report is sending very unique information about your system - like a fingerprint, if not stopped with shell commands. See here: https://www.howtogeek.com/349844/how-to-stop-ubuntu-from-collecting-data-about-your-pc/
update: answer below argues that permission is asked before actually sending this information.
But now, I also frown upon a fresh minimal Ubuntu image connecting to the internet upon login. When logging in to the console, a Message of the Day (MOTD) is displayed. Something like this:
ubuntu login: ubuntu Password: Last login: <date> Welcome to Ubuntu 18.04.1 LTS (...) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage System information as of <date> System load: 0.08 (..) Usage of /: 4.9% (..) Get cloud support with Ubuntu Advantage Cloud Guest: http://www.ubuntu.com/business/services/cloud 0 packages can be updated. 0 updates are security updates. Failed to connect to https://changelogs.ubuntu.com/meta-release-lts. Check your Internet connection or proxy settings
Perhaps I am being paranoid, but I think it is unacceptable that a mere login would send anything to the internet. If you do a connection to 'changelogs.ubuntu.com' every time you login on the shell, that can lead to potential security and privacy concerns. Am I the only one who is surprised about this and finds this unacceptable?
My question is: how can I safely use Ubuntu without compromising security or privacy?
In particular, my concern is with sending anything to the internet without permission. I don't want things to automatically connect or check or update to the internet in any way, unless I give the command to do that, with
sudo apt update for example.
I tried playing with
/etc/update-motd.d scripts but I could not find the script that was the culprit. I am kind of annoyed that I wasted a good hour on this stuff and still don't trust my Ubuntu system with ethernet/internet until this issue is resolved properly.