Instead of counting strikes and threatening with massive lawsuits, can't they simply throttle for 30 days if there is a copyright notice? Fair "punishment" for the crime, and also negligible effect for falsely accused. Some people might know they are downloading and when the notice comes and subsequent throttling, they are not surprised. Some other people might decide to live with the effect and not go on and secure the wifi. Some might go around and fix holes in their computers, scold their children, change wifi password. And switching carriers is always an option if one is firmly believing they are not doing anything illegal.
But, no throttling without the associated notice. There should be no excuse for lazy ISPs that won't upgrade their network. Talking about cable here, not cellular data and limited spectrum.