dhayman I sense you feel very strongly about this issue as most of do. Google I highly doubt appreciates this spam and is probably trying their best to correct the problem.
I noticed a few things the domain xxx.casinos777portal.com has very little to do with the problem. The legitimate sites were set up before this domain are the culprits.
What is happenning here a group of people with legit sites got together and did this. How do I know? because the people taking part already have indexed pages on google.
I could find the answers for you, but would require a long term search. I do have partial answers but nothing concrete.
Now that you have posted this information I would like to ask what do you plan on doing about it?
greek39