Earlier quoted context omitted.
> They are welcome to try. And I am welcome to try harder to block them. Technically, Facebook could insert news feed ads like a post from one of your friend (assume that the friend has liked some page or organization). It could be tough to distinguish between ads and posts much like native advertising.
Ads already affect the experience significantly, this would do so even more. (not that I use Facebook, but Tumblr for example, has extremely annoying repetitive offensive ads)
And people still go on about blocking ads being unethical