You joke, but even some of the most poorly engineered streaming services, like Crave.ca, managed to implement screenshot blocking.
Seriously, this is a service whose Android app always appears as "unavailable in your region" (I'm in Canada), yet it allows mobile browsers to play the content just fine, except for the screenshot blocking.
And also the drivers of your videocard will prevent outputting such data via uncertified cables.
There will also be a hidden watermark in case you want to take a picture of it with your camera, which ofcourse is not allowed.
/s