He's referencing that we have early 20th and late 19th century case law about third parties holding documents, etc, that is used to make everything sitting at a cloud service subject to subpoena without a warrant (email, etc, too).
There's all kinds of precedent that was based on sane tradeoffs for the 1800's that doesn't make sense anymore with the more complicated ways we transact and interact and with the ability of technology to commit mass surveillance.
The problem has only been super significant for 15-20 years, which is a blink of an eye in this sense; not even enough time for the populace to really understand and appreciate the issue.
It is, of course, still broken.
And in this case, judicial precedent follows evolving (both popular and legal) ideas of what the words in the constitution mean.
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures..."
"Persons, houses, papers, and effects" has been interpreted in terms of what things a person had, excluding things that they had given someone else to hold. It was a pretty reasonable interpretation and compromise, until it was the governing case law that covered the cloud.
Legislation can limit what Federal agents are allowed to do totally irrespectively of whether those things would separately violate the constitution.
And in any case: the law is a blunt instrument. It's (usually) better as a slowly changing representation of conventions and social consensus instead of something that we make sweeping changes in (whether legislatively or judicially).