I'd be surprised if they went to too much effort with this. I think they have to appear as if they give a shit, but really, they know that by cracking down on this they risk losing customers, and I'd be surprised if they genuinely gave a shit that people in the UK were accessing obscure Brazilian day-time soaps for example. Whether people are using VPNs or not, the important thing (for them) is that those people are pumping money in to Netflix each month.