Well, professor, seems to me that:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated
Seems pretty absolute to me.

Of course, there's that old shibboleth "expectation of privacy".

Well, of course, there is no "expectation of privacy" anymore, now that government has constructed a 24/7 surveillance grid all around us.

GPS should be fair game in police probes


...Unlike the First Amendment, which is worded in absolute terms -- "Congress shall make NO law" -- the Fourth Amendment bans only unreasonable searches. That is, it recognizes that there is a whole category of searches that are fully legitimate and violate no one's rights.

As to what is reasonable, it obviously changes with the circumstances. Given that criminals can use freely all the new technologies -- including of course GPS trackers, smartphones and spyware -- it seems eminently reasonable that the police should also be able to use some of these, especially in public spaces, in which people have no expectation of privacy (or at least should not have one)...