It is on this page:
http://www.pinwiki.com/wiki/index.php?title=PinWiki:Copyrights

"The copyright for original material posted to PinWiki.com remains with the author, but by publishing it to PinWiki.com, the author grants PinWiki.com an irrevocable license to display that material. To receive an exemption from this irrevocable license you must receive express written permission prior to the submission of content. By submitting material to PinWiki.com you acknowledge that you have the rights to grant this license."

You can find some info on who owns the domain and runs the site here:
http://groups.google.com/group/rec.games.pinball/browse_thread/thread/d9b3b76e6a505d3a

Some more info:
http://groups.google.com/group/rec.games.pinball/browse_thread/thread/ad9956996eef7e71

When Pinwiki was started, I brought up the licensing issue on KLOV right away because I didn't want to see everyone's work disappear. Casey replied that he was going to use the same license as Wikipedia. As you have brought up, it isn't spelled out extremely well on the current site. I believe the intent of the current license is to try and keep someone from contributing content and then taking their ball and going home. But it does come off as restrictive rather than permissive. I don't think that was the intent, but it is good to have everything spelled out and clear so no problems arise in the future. The KLOV thread where this was discussed is here (see post #31):
http://forums.arcade-museum.com/showthread.php?t=180989

Casey seems pretty open to discussion and making things available, so I'd think he'd respond if your concerns were addressed to him directly.

I'm certainly not pessimistic, and I don't think PinballHelp is either. I use Pinwiki and I'm a contributor (I wish I had time to contribute more.) Our concerns are about making sure the content is freely available and can't be locked away. Sure the site may be mirrored, but that does not address the rights to the content. There are tons of different licenses that are permissive but still retain rights for the creator of the content. Pinwiki needs to decide which one is used and state it right up front so that contributors know or can find out how their contributions will be handled. I brought this up right at the beginning because it is easier to get in front of this issue rather than try to patch it up after the fact.

I'm no expert on copyright, I'm just a bystander who kind of pays attention to this stuff and often sees what a mess is created.

Yes, we're both saying the same thing and have the same concerns. I raised them over a year ago when the site started. As I said earlier, I think Casey intends for the content to be freely available. But as you point out, as things are currently worded it isn't that way.

PinballHelp, have you read any of my responses other than the first one? Sorry if this response comes off as snippy, but I feel like everything I've stated is splatting on the wall. I pointed out who runs the site (Casey, it isn't Chris Hibler). I pointed to the thread on RGP where he introduces himself. I pointed out on KLOV where he said he intended for everything to be open. We can debate this here ad nauseum, but until this is addressed to Casey (who runs the site), nothing will come of it.

I admit I haven't taken the time to raise the licensing issue with him again. And I probably won't as it isn't on my "to-do" list at the moment. I do share concern about it and I think it is a valid thing to worry about, and it can be fixed with the use of the proper license and terms. But I freely admit that I'm not going to be the torch bearer for it at this point in time.

Edit: Here's more: http://www.pinballnews.com/learn/pinwiki/index.html