> It is pretty indisputably unethical as it breaks the social contract of the service delivery.
I would dispute that there is such a social contract, any more than there is a social contract that if you download a patch to fix DRM, you are implicitly agreeing to install the virus it comes with.
Ad-funded businesses are engaging in market dumping, subsidizing their offerings by poisoning the minds of billions of people, and creating anxiety, insecurity, and dissatisfaction in the process. If someone gives you something for free covered in lead dust, and you accept it but clean the dust off first before touching it, I don't see the ethical quandary. Particularly when you know their widget cost them a fraction of a penny, and they were being paid to give you the poison.
Like Bill Hicks said, these people are Satan's little helpers. Engaging with Satan and undermining him may be unwise, but it's not unethical.
As others have pointed out, these people also have a level of stalking going on that I don't think the average person (or even a relatively informed person) can grasp, and so there's no possibility for a social contract to exist there.