Valid concerns and the question does need to be asked. I was curious of this too so a couple months back I had a lawyer friend of mine attempt to look into MDGC.
What he found was the patent info that I had already seen, but he did verify that it was real. He found that there is a company, which we all know. But, other than a few random facts that he came across, thats about all he came across due to the lack or reporting by the company and its excessive lack of presence. But, he did assure me that this was not at all uncommon with these types of companies.
Unfortunately, in order to find out more he would need to make an official request to the other partners of the firm. And this particular firms DD process quite frequently has a $1,000,000 + price tag attatched to it.
Anyways, to sum it all up, a lack of available information/publicity is pretty common as I am sure you already know and is not ALWAYS a bad sign.
But trust, I understand your concern 100%.