From Wikipedia,
Following the dismissal of FBI Director James Comey on May 9, 2017, New Jersey Governor Chris Christie presented to President Donald Trump the possibility of hiring Wray as Comey’s replacement.
So fire the dude you appointed and replace with someone more loyal. Well this will go well /s
Except now they know the individuals using your Internet.
Sure if you live alone they already can easily put that information together. However if you have a partner, a relative and children all living in one house they now know who is in that home.
Plus maybe no one in the house uses Twitter and Aunt Alice the Twitter user came to visit, does she need to reverify? Your ISP knows that now.
ISPs would be gaining a lot of new information.