To quote from their website

The DLC is a non-profit organization improving energy efficiency, lighting quality, and the human experience in the built environment. We collaborate with utilities, energy efficiency programs, manufacturers, lighting designers, building owners, and government entities to create rigorous criteria for lighting performance that keeps up with the pace of technology. Together, we’re creating solutions for a better future with better lighting.

And I'll bet that most of you have seen the "DLC Listed" symbol on an LED lighting product when looking at a manufacturer's website or product page.
What are your opinions on this organization?
Obviously there will always be Chinese companies that abuse the mark and use it without permission, and there is an entire section on their website for violations.

Never heard of them. And I don't want a "human experience", whatever that is, sounds ghastly 

 I'll stick with incandescents and HID, thanks. Oh and LPS, of course 

Chinese companies have been abusing the CE mark for years.! 
So much so that in some circles it stands for Chinese Export. 
I've even heard some people say it stands for Caveat Emptor 

Do you watch Bigclive? He likes to use the term "Caveat Emptor" to describe the abuse of the CE marking on cheap Chinese electronic devices.
BTW there is a section in the "CE mark" Wikipedia article about "China Export"

Used to watch him a lot, but not so much now since all he seems to do is mess with cheap Chinese crap, which I have no interest in whatsoever, except to try and ensure I never buy any.

And he keeps calling circuit diagrams "schematics" which is irritating in the extreme