How do you know that don't? This could explain the exploding health care costs! :)
I don't, but I've never read an item in the financial news that Blue Cross is a subsidiary of Visa. In all honesty, I doubt that the MBA's at MasterCard have even thought of cross-pollinating their business this way.
As for health insurance, it really needs to be taken out of the for-profit, public company model and into the regulated-profit, monopoly, utility model. Like Con Ed. The genius of America has been that it has always been able to jump over socialism with the utility model for necessities. Health insurance is now as big a necessity as electricity, but it would be a disaster if it became socialized (single payer is the socialists euphemism).
The public employee union pension funds would be a good place to start selling a health insurance utility companies stock.