The NSA has had dragnet surveillance of most or all of the US internet for some years. If that's not a 4th Amendment violation, then nothing is.
If you want legalistic, narrow (razor thin!) interpretations of all "rights", then they're not really rights, they're just something for lawyers to natter on about. Further, Lee Greenwood's "Proud to be an American" becomes nothing but parody.
Even assuming that were true, I disagree it would be an archetypal 4th amendment violation. Privacy on the Internet doesn't exist as a matter of fact. Anyone who controls a router between you and your destination can see your Internet traffic. When you try to apply the 4th amendment to the Internet, you're not asking the government not to intrude on an otherwise private space (i.e. the heart of the 4th amendment). You're asking it to indulge a purely legal fiction of privacy.
If data isn't encrypted, it's simply exposed to too many people for any expectation of privacy to be "reasonable." If the government has a warrant, that has always meant the power to coerce people into opening locks. And the Constitution does not apply to foreigners abroad, and to searches at the border. These are not just legal technicalities, they are well-accepted limitations on the power of a 200+ year old document to override the decisions of a democratically-elected government.
Also, since keys are trivial to hide and destroy, it's also impossible to prove who thwarted a search.
In other words, the same level of care that it takes to go up against a state actor unconstrained by the law would easily thwart a supposedly legal warrant.
State power isn't absolute, and states will have to get used to that.
If I keep an unlocked box full of papers in my neighbors garage, and he sometimes rifles through them looking for something interesting, can I say that box is "private"? Maybe if the box is locked and only I have the key (I.e. Client-side encryption) but not if I send it to him locked but give him the key (I.e. HTTPS). Again, it's not about legal technicality or technical technicality. It's about whether the information is actually "private."