> third-party doctrine, the 1970s-era Supreme Court case holding that there is no privacy interest in data voluntarily given up to a third party like a cell phone provider.

I don't think the issue is how the cell phone companies give the info to the government (voluntarily or involuntarily), but rather that because you, the consumer, "gave" your location info to the cell phone company "voluntarily", you have no privacy rights with respect to that info.

Quotes because the definitions seem fuzzy to me (and to the defendant's lawyers, apparently).

I am not a lawyer.