There should be a law to enforce giving and accepting 'no' as an answer. I'm seeing "not now" everywhere nowadays, and it started to make my blool boil.
I can and I am already using all sorts of blockers at different level that even if I said yes at some point the data isn't going anywhere, but enough is enough, it shouldn't be an arms race to protect very basic privacy or simply having dignity in front of my computer or cellphone.