[londons_explore]

I would guess that if you can get payouts from some small chunk of users, you can then use those funds to 'reinvest' in tracking down and catching more.

As soon as the process is sufficiently automated to be margin positive, you might as well scale it up to the whole population.

[ExoticPearTree]

I think it has to do with the fact the ISPs are responding to requests automatically and don't fight for user privacy.