The thing you're forgetting in your "true business case" is that you have to pay money to fight the unauthorized video streams. Avoiding going down that road is worth a great deal of money in and of itself, since it is doomed to failure.
This goes back to the old argument of whether IT is a cost center or a revenue generator.
One problem is that it can be either; it entirely depends on the skills and training of the IT department.
The other problem is the difficulty in how to measure the revenue generated by IT. The old adage is that saving a dollar is the same as making a dollar, but those dollars that get made are a lot easier to find in the financial reports.