My patience is over, legal action to go
 

OK, that's enough. I only need this information: who is the one I have to sue?

Is it Apple, or Synaptics? One of these two companies causes my streaming video is disabled when I connect an external display to my laptop. I believe none of them has a privilege to block my streamed video, and my patience is over. I pay for streaming services, I can receive all the video content legaly, but DisplayLink installed on my MacBook causes I can't see anything. Unfortunatelly, DisplayLink is the only way I can connect my external display to watch these videos – but if i do so, the software blocks it.

I've already contacted my lawyer and I mean it. Now, the only thing I need to know – just to save our time – who is to be blamed? Should I sue Apple, or Synaptics? Or both?

I don't want to make you sad, but neither Apple nor Synaptics causes your (and my) streaming video to be unavailable during using DisplayLink software. All those streaming platforms have decided to implement a mechanism to prevent users from recording their content. If the web services, through API provided by Apple, detect that you are recording your screen (if you are recording your screen, it is a huge change that you are also recording their content), they are disabling video. They might not do this, but they've decided to do so. I have not checked their term of service, but I believe that such a "feature" is mentioned.

I understand that. The problem starts a bit further though: either Apple or Synaptics tell the (Netflix/Disney/HBO) player I'm "recording the screen" – which is not true. I am not recording my screen. I've just attached an external display using DisplayLink driver. And this configuration is set up wrong way, so that a third party software get the (wrong!) information I'm recording the screen. That's the core of the problem. Either Synaptics or Apple lie about my configuration, pretend that I'm recording something even it's not true. This is what's it all about.

btw, you know what the fun part is? If I actually record the screen, i.e. using the system screen recording in MacOS, it works. Nothing is blocking the playback and I can record the stream/screen freely.