They are welcome to try. And I am welcome to try harder to block them.
As long as they don't try to force some sort of legislation on how people can use their internet connection, and their internet browser to fetch and display content, there's no problem.
The real problem is Facebook is already full of advertising disguised as content. From sponsored posts to content from things you "like". So I'm kind of surprised they need to go out of their way to explicitly announce that they will be disguising ads. They already have the power to inject it in the middle of content invisibly.
As long as they don't try to force some sort of legislation on how people can use their internet connection, and their internet browser to fetch and display content, there's no problem.
The real problem is Facebook is already full of advertising disguised as content. From sponsored posts to content from things you "like". So I'm kind of surprised they need to go out of their way to explicitly announce that they will be disguising ads. They already have the power to inject it in the middle of content invisibly.