if they generate a million people's world of CO2 each, that's the pollution of 3 billion people!!!

Which is why I doubt that that's true. For it to be true, you'd probably have to do some kind of calculation like "if this privately owned company is owned by a billionaire, then assign all CO2 emissions from its entire operations to that one individual". So, if you eliminated them, you actually wouldn't eliminate those CO2 emissions. Someone would take over that business and it would continue putting out CO2 as long as someone was buying its products and/or services.