This seems very strange to me. I'm running kernel 18.104.22.168 and ran:
~]$ cp -r /proc/ here ~]$ rm -rf here
I get some permission denies when copying as expected and I eventually hit Control-C. I get
Permission denied on a lot of files when trying to remove the new directory and files.
As a note, I found this weird behavior because a friend sent me a
.tgz of a snapshot of his
/proc dir. I extracted the directory and when I was finished looking through it I had the same problem.
rm -rf as root does work.
lsattr shows the e attribute (which is what all of my files/directories show).