It's not a completely ridiculous legal interpretation. The 4th amendment is implemented via the exclusionary rule, which excludes evidence from a court case obtained from an unreasonable search. As a matter of history and practice (the exclusionary rule predates the Constitution), the 4th amendment is in many ways a rule governing criminal procedure more than it is a privacy rule per se.
Now, today the prevailing view is that the 4th amendment is that illegal searches are unconstitutional even if the exclusionary rule can't be invoked (see, Bivens v. Six Unknown Named FBI Agents), but there is still this contour in the law that distinguishes collecting data from trying to bring it into evidence.
The argument here is probably wrong, but not ridiculous.