It's probably misplaced to focus only on NSA in this respect, but if we talk about government electronic surveillance capabilities generally, they've been expanding through many agencies and parts of government. ACLU's recent focus on local police use of IMSI catchers is just one example; they started out as super-secret high-tech spy stuff and now local cops think they're super-awesome and are afraid they may to have to give them up if word gets out and the courts or legislators start taking a closer look.

Electronic surveillance used to be more stigmatized in some ways, but it's becoming more culturally normalized as a basic government tool (at least in the culture of government agencies -- I hope not as much elsewhere). So you see it used in more and more contexts.

I'm totally unfamiliar with the raw milk regulations, but I think that people who are concerned about them could reasonably worry that electronic communications surveillance will be used to enforce them in the future. Likely not by NSA itself, but perhaps through something that's in part technological trickle-down from NSA development or procurement.