[walrus01]

No residential last mile broadband ISP at the scale of hundreds of thousands or millions of customers is presently willing to spend the salary/benefits/fully loaded employee cost on the massive teams of (somewhat technically clued in, not low wage) people it would take to effectively implement this.

[account42]

They would be willing if they were themselves held liable for the illicit activity originating from their network otherwise.

[justcool393]

except we need ISPs to be treated as relatively neutral parties. we don't hold the water company liable if someone uses water to cook up meth