There is an argument that bypassing cryptographic and security features is a violation of the DMCA and therefore a copyright violation (not piracy unless you distribute though), but that's also a gray area. E.g. I flashed my Bluray drive with software that allows copying the raw footage after it has been decrypted, so I'm not breaking the encryption, I'm just bypsasing it by copying the decrypted content while it's in memory. I'm guessing that's covered under the DMCA.

But blocking ads is nothing at all like that. I'm not breaking any security measures, I'm just not loading their ads. It's like a DVR only storing the non-ad parts of the video, and those were commercially sold and AFAIK totally legal. I am not legally required to download everything the website asks for, requiring that would be insanity.

And yeah, I could completely avoid these companies, and I could choose to actually pirate content and likely totally get away with it. But what I'm doing (blocking ads, bypassing copyright on content I own and not distributing copies) is in a gray area. Blocking ads isn't illegal AFAIK, and ripping DVDs and Blurays is in a gray area of the DMCA because I own the physical media (so it could be considered a "backup," which is allowed).