Does something like running the duckduckgo extension not help?
No, yes
Yes, giving these people short (or long, mēh) prison sentences is the only thing that will stop this.
No, the obvious grassroots response is to not use LinkedIn or Chrome. (You mean developers not consumers, I think. The developers in the trenches should obey if they need their jobs, they are not to blame. It is the evil swine getting the big money and writing the big cheque's...)