The fourth amendment is to protect you against being arrested and deprived of life, liberty or property without due process. A warrant is part of the process in making sure that an arrest is justified.
Intelligence agencies have no authority to arrest you, nor would they have any interest in doing so. Their job is to gather information about what other countries are doing that might be harmful to the US.
Even then, I think warrants generally aren't required for publicly available information.
> The fourth amendment is to protect you against being arrested and deprived of life, liberty or property without due process.
Privacy is liberty and property is property. Unreasonable search and seizure is unreasonable and prohibited (even if there is no current effective remedy) in all cases, not just criminal justice.
> Even then, I think warrants generally aren't required for publicly available information.
This does seem to be the decisive issue in this specific case.
> Privacy is liberty and property is property. Unreasonable search and seizure is unreasonable and prohibited (even if there is no current effective remedy) in all cases, not just criminal justice.
Your water utility voluntarily selling information about your water usage to the government is not unreasonable search and seizure, and does not deprive you of any property.
I don't think you're going to meet a lot of legal success by framing privacy in this context.
> The fourth amendment applies to the state, not just law enforcement
In principle, yes.
In practice, due to the absence of meaningful remedies other than the exclusionary rule, not so much.
Rules are only as strong as the consequences for breaking them.
(But this doesn't seem to be a violation, anyway; data in a custody of a third party that is legally permitted to sell it publicly is neither being searched nor seized when it is purchased in a mutually-voluntary exchange by the state.)
It is not so much as spying for law enforcement, but spying to protect their power. The military industrial complex invented the boogeyman and use their intelligence arm to promote it.
