The Supreme Court said that people have a reasonable expectation of privacy while using the phone, and that therefore the 4th Amendment applied. Part of the reason people had that expectation was that Congress had introduced much stronger regulation of telephone circuits in 1934 so it wasn't like just anybody was allowed to tap into utility lines.
However the only protection is the expectation of privacy, which Congress can take away by saying "you should not expect communications to be private in these situations". And that's exactly what they did in 1968 in response to those Supreme Court decisions.
One important provision of that law were that the President was allowed to take "such measures as he deems necessary:"
to protect the nation against actual or potential attack or other hostile acts of a foreign power, to obtain foreign intelligence information deemed essential to the security of the United States or to protect national security information against foreign intelligence activities.
EMails have less expectation of privacy, though Congress did try with ECPA (which was passed when POP was the way to obtain email, not IMAP). But even ECPA gives broad exceptions for FISA surveillance.
Part of the reason people had that expectation was that Congress had introduced much stronger regulation of telephone circuits in 1934 so it wasn't like just anybody was allowed to tap into utility lines.
I wonder how well we would take it if we discovered that in addition to the NSA, Gmail was also sending all communications directly to Joe Blow in Podunk, Indiana, for his personal edification and entertainment? After all, it's not like we had any expectation of privacy for our email. What laws would this violate?
Well, is Joe Blow a Google employee? It might not break any laws at all in that case.
If he's not a Google employee it would probably violate ECPA, but ECPA explicitly allows foreign intelligence surveillance to occur (even over the Internet), so that wouldn't help against government surveillance being done in accordance with FISA.
No, Joe Blow is just some random dude. He did Sergey a solid once, and in return he gets access to all of Gmail. ECPA is a dead letter, and was specifically about government not private actions anyway.
My point, which admittedly I'm still not making clearly, is that it's weird to consider phone calls to be some sort of judicial fluke that was far outside accepted 4th Amendment jurisprudence. Americans didn't want the government listening in on their phone calls. Since we clearly couldn't elect a government that would abstain from that noxious practice, it was a good thing the third branch stepped in for a time to stop it. Maybe sometime in the future we'll be that fortunate again.
If one is uncomfortable with the Joe Blow example, consider how much worse it is for the government to be reading all of Gmail than it would be for Joe Blow to be doing that.
The Supreme Court said that people have a reasonable expectation of privacy while using the phone, and that therefore the 4th Amendment applied. Part of the reason people had that expectation was that Congress had introduced much stronger regulation of telephone circuits in 1934 so it wasn't like just anybody was allowed to tap into utility lines.
However the only protection is the expectation of privacy, which Congress can take away by saying "you should not expect communications to be private in these situations". And that's exactly what they did in 1968 in response to those Supreme Court decisions.
One important provision of that law were that the President was allowed to take "such measures as he deems necessary:"
to protect the nation against actual or potential attack or other hostile acts of a foreign power, to obtain foreign intelligence information deemed essential to the security of the United States or to protect national security information against foreign intelligence activities.
EMails have less expectation of privacy, though Congress did try with ECPA (which was passed when POP was the way to obtain email, not IMAP). But even ECPA gives broad exceptions for FISA surveillance.