I sent him the following PM:
Lireci,
This is a quasi-formal notice from the SCP senior staff. Somebody noticed your SPC wiki and pointed it out to us, at which point we took a look at it. While you've made an effort to attribute the originals through the link mentioned in the history, we typically insist that any reproductions of our work include the author's name as a part of the attribution (somewhere, at least; how you handle it is up to you, as long as the author's name is attached to the page somewhere). It's not only common courtesy when reposting someone else's work to mention the original author of the work, but it's a specific requirement of the Creative Commons Attribution-ShareAlike 3.0 License, under which both our wiki and yours are listed.
We hope this can be fixed comparatively soon and without difficulty.
—Eskobar
Moderator, SCP Foundation Wiki
Sound good? I figured it wasn't a great heaping deal, especially since the user hasn't done so much as make a forum post since December and she's probably not coming back. Also, as Rhett pointed out, he did make an effort at attributions, just left the author off.