They can put enormous pressure on even the wealthiest and most powerful companies to act as copyright police on their behalf. Even Google is afraid of them. ISPs are forced to spend huge amounts of time and money working for them. Now duckduckgo is being strong armed into doing a bunch of free work for them too? Maintaining lists of websites and domains to block and removing links to even non-infringing material like youtube-dl just to keep from being sued into the ground.
I don't know what it'll take to rein in these guys, but I doubt the courts will be the ones to do it. So far courts seem fine with the idea that ISPs must permanently ban users from their service over nothing but repeated unsubstantiated claims of infringements which is an insane amount of power to give any industry.
Has any US politician ever run on a platform that includes copyright reform?