Mashable reports that users ran into a black screen on YouTube, and that it stayed for about 6 seconds before the video began playing. The reports indicate it affected several browsers including Firefox, Edge, Vivaldi.
Some users joked that they would rather see a black screen than an ad. While that's certainly a better experience, it does waste precious seconds of our time. A simple workaround for the black screen on YouTube is to just refresh the page, hit F5 as soon as the page starts loading. uBlock Origin's filters were updated with a patch to resolve the problem, the add-on updates its filters automatically. If you are still experiencing the black screen issue, just open the extension's dashboard and manually update the filters. This tug-of-war is getting annoying, but it appears to me that Google's efforts are actively promoting the use of ad blockers, instead of attracting new subscribers.
It could also go the other way and someone could sue Google or other companies. Web browsers and ad blockers run on the client not the server, generally with the authorisation of the owner of said client system. It is a technical measure to prevent unauthorised code (i.e. unwanted ads) from running on the system, imposed by the owner of the system. Anti ad blocker tech is really an attempt to run software on someone's computer by circumventing measures the owner of said computer has deployed to prevent that software from running, and has not authorised it to run. That sounds very similar to the definition of computer fraud / abuse / unauthorised access to a computer system / illegal hacking in many jurisdictions.