Earlier quoted context omitted.
There needs to be further refinement as to what actually constitutes "watching", e.g. with respect to duration, frequency, information monitored, etc. US v. Jones held that installing a GPS device on a car constituted a trespass against one's "personal effects". I think the similar argument here would be that a near constant observation of someone, even while in public, would amount to the same sort of search, even t…
Jones was based on the classic idea that when the government does what would be a trespass if a private person did it, then a warrant is required. Observing someone in public is not a trespass, no matter how much you do it.
Swap "GPS monitoring" for infrared, EMF, video, audio tracking, whatever those planes are doing, and I think we are at the same level of "impinge(ment) on expectations of privacy."
Is it your opinion that Alito and Sotomayor are barking up the wrong tree? Is this sort of extensive (i.e. multi-modal (visual, EMF, etc.)), and evidently prolonged, monitoring not an impingement on typical expectation of privacy? Sure, this isn't a trespass, but if a private person was doing this to you, wouldn't you want to call the cops? (Oh, wait...)