Superman: I am Human Too, Published: 03-26-08 - Updated: 04-09-09
The original story is by Yvonne Connell: Go Softly Into the Night, submitted to the Lois and Clark archive in October 2006.
Plagiarised story, with upload date highlighted
.Original story, showing upload date:

I took a quick look at the author's other work and the first story I clicked on also appears to be plagiarised, unless the author is also Elizabeth Wilde of the Rogues and Wolverines fandom (which I doubt, looking at the quality of a third story I clicked on and the quality of the writing in the author's profile.
Homecoming is word for word Missing by Elizabeth Wilde, minus a poem White quotes at the start of her story. Wilde's story is uploaded on 10/07/2000, while Homecoming is uploaded on 05-21-03.
Second plagiarised story:

Original story:

Original story upload date:

Sorry the screencaps are so small; I hope you can read them.
Thanks so much for your help with this case!
April 10 2009, 04:45:08 UTC 3 years ago
Thank you for taking screencaps. And good guess about the other fics. Turns out I've been able to identify all but one appear to have been written by others. And I'm fairly sure someone else will recognize, No Place Like Home.
I'll contact Shin-kalel/journey2forever as well as as many of the other authors as possible.
April 10 2009, 04:58:02 UTC 3 years ago Edited: April 10 2009, 05:03:36 UTC
ETA: the plagiarised Lois and Clark fic appears to have been deleted, as has the comment in the author's profile that more Superman fics were coming soon.
April 10 2009, 05:30:00 UTC 3 years ago
I tried contacting the various other original authors, but it seems that most of those emails are old enough that they aren't still in use and are bouncing, so if your friend has better luck reaching folks, do let me know.
Thanks!
April 10 2009, 05:33:29 UTC 3 years ago
April 10 2009, 15:08:53 UTC 3 years ago
Anonymous
April 10 2009, 05:47:33 UTC 3 years ago
I am sorry for having posted the work of others. I just wanted to start with existing stories so I would be able to make my own, and believe me, I have made a few of my own already thanks to those I published. I didn't know that publishing those would lead to chaos.
Again, my heartfelt apologies, and starting today, I will remove my account from FanFiction.net, never to go to that site, or any other site again, to post anything.
I'm sorry for my shortcomings, I humbly beg forgiveness from you and the authors.
Shin-Kalel
April 10 2009, 15:07:11 UTC 3 years ago
April 10 2009, 19:00:46 UTC 3 years ago