If they really start doing this, it's time to rent a seedbox.
Once the vast majority of casual piracy is curtailed, more more focused enforcement against people on private trackers / seedbox providers etc can begin.
Sure there will be loopholes and ways for determined pirates to slip through the cracks, but the days where everyone and their brother can grab pirated content without worry are numbered.
Not on any of the private trackers that I use. The speed of the downloads has never been an issue because there are already a few people with seedboxes on every torrent, ensuring that downloads are always fast.
Moreover, this program is only in the US, where people have super shitty Internet speeds anyway - most of the times I'm downloading and there are no seedbox peers, it's someone in Europe with a fast connection who's sending me the bulk of the data. Those people will keep downloading regardless of what happens in the US.
Finally, the types of people who frequent private trackers are exactly those who would be willing to rent a seedbox. Ultimately, this will only hurt the ISPs. Right now I pay for the fastest U-Verse connection I can get. If AT&T starts sending me these notices, I'll just downgrade my speed and use the leftover money to rent a seedbox.
Actually watching things on a physical tv?
Yeah, this enforcement will likely expand beyond the US as they are pressing very hard in every trade negotiation. But legal options will expand over time as well.