[iguy]

prepaid SIM card (in the US), I bought it on eBay

This is highly unusual now. For instance most countries in Europe will now need to see your passport to enable a SIM card. So India isn't an outlier. The stated reason, I believe, is terrorism. Whether this is Orwellian I leave for you to decide.

[Zak]

Yes, that's highly Orwellian and terrorism is an absurd justification. Anybody capable of pulling off a terrorist plot requiring a phone is likely to be able to find a way to get one without such a regulation making a problem for them.

What it does enable is surveilling a person's location and some of their communication without having to do something requiring resources and the possibility of alerting the person that they're a target.

For the record, it's not unusual to be able to buy and use a prepaid SIM card anonymously in the US. There have been a couple proposals to ban it, but they came nowhere near passing.

[iguy]

Sorry, by "highly unusual" I meant more an outlier among countries (in which I've bought sim cards).

I guess I now assume it's all so tracked as not to matter much one way or the other -- it's not like the NSA can't connect your ebay account to your name. Asking for ID just saves them a few CPU cycles, reducing everyone's carbon footprint :)

[Zak]

I think they'd have to work a bit harder than that.

Even assuming they have continuous access to ebay, telco and mvno systems, they probably don't have continuous access to the computers of the individual reseller who's selling preloaded SIM cards. This is almost certainly one guy working out of his house.

No doubt, the NSA could hack that guy, but they'd have to do so deliberately. The connection necessary for mass surveillance is broken at this point.