It's hard because non-fraudulent corporations commonly have very complicated ownership structures. The global corporation owns the US subsidiary which owns the Auto subsidiary which owns Auto Parts subsidiary which owns the Northeast Region Auto Parts subsidiary which owns a subsidiary that makes transmissions which owns a subsidiary that makes warranties for transmissions etc. etc. The level of complexity necessary to confound an external investigation is not inherently less than the level of complexity that exists in legitimate real corporations.
Corporate ownership is also traded as a commodity. The US Auto Parts Northeast Region Transmissions Warranty subsidiary is required to hold assets sufficient to bond the warranties it issues, so instead of keeping a large pile of hundred dollar bills on the coffee table, it holds shares of the parent company and you now have circular ownership. If the parent company is loaded up with debt then you might find that the subsidiaries like that own the majority or entirety of the parent company -- without even necessarily realizing it.
You also have the problem that people willing to commit fraud are willing to commit fraud. Convince some credulous victim that all they have to do is put in $1000 and sign some papers and they can invest in The Next Big Thing and they've not only scammed them out of $1000, now it's the victim's name on the shell corp.
Generally speaking identifying people who don't want to be identified is hard, the methods effective to do so oppress innocent people more than anything, and it is best to look to other solutions. For example, if you discover people are publishing misinformation, show the truth to the same people who saw the misinformation.