It's scared them off SOPA-like activities.

https://torrentfreak.com/sopa-ghosts-hinder-u-s-pirate-site-blocking-efforts...

The main reason why pirate site blocking requests have not yet been made in the United States is down to SOPA. When the proposed SOPA legislation made headlines five years ago there was a massive backlash against website blocking, which isn’t something copyright groups want to reignite.

“The legacy of SOPA is that copyright industries want to avoid resurrecting the ghosts of SOPA past, and principally focus on ways to creatively encourage cooperation with platforms, and to use existing remedies,” Turkewitz tells us.

- d.