Whether one "has" a warrant or not is clearly not a privacy issue. A warrant is not an attribute of a person, despite the fact we say a person "has" a warrant. I think the terminology confuses the issue that way, because it lumps having a warrant in with other things a person "has" or "has on their person" etc. that clearly are a privacy interest and w.o certain cause, compelling reason, etc. should not be the kind of thing a law enforcement officer or anybody else for that matter should just be able to find out about.
Example: a person has a medical condition. Privacy interest. There must be certain factors present for a law enforcement officer to inquire about same, or for that matter for anybody else to.
When I am going to book somebody at the jail, prior to transport for instance, I will ask about medical conditions, for the person's safety WHILE IN MY CUSTODY since that is my responsibility. In that situation, it's reasonable for me to ask does the person have something like diabetes, where depending on when they last shot up/ate etc. they could pass out etc. during the transport, or do they have a joint injury that would make wearing handcuffs problematic, etc. We certainly don't ask about HIV etc. but only conditions that would be dangerous to fellow inmates (highly communicable, like Hep B), or dangerous to themselves durimg transport or incarceration (hidden absess for instance. Not at all uncommon amongst IV drug users and often a serious and even potentially fatal condition. If they have an absess, they go straight to the hospital, not the jail, and often we will forego booking and just leave them at the hospital to be treated, etc. suspects may be hesitant to admit to being an opioid addict for instance (especially in a case where I found drugs on their person since they perceive it could incriminate them - help support that they would be a person who would have drug X on their person, or under their car seat or whatever. I will encourage suspects to admit same to the jail nurse, so that they can receive treatment during their incarceration/withdrawal that will at least make the withdrawal a little more tolerable (antihistamines, possibly something like clonidine or suboxone as well, etc.). In the case of withdrawal from alcohol, as opposed to opioids, that can be a potentially fatal condition, as well and it is logical and reasonable for us to ask, FOR THEIR safety, and because it's out responsibility, etc. And fwiw, I will never document a medical condition, that I learn about through such screening, on a case report, because it was asked as a matter of privacy and for their safety and not for public knowledge. nothing I, or a nurse or a booking officer asks about medical conditions for the purposes of their safety/others safety during incarceraton will be used against them, as it should be. But at least we have valid, articulable reasons in that case to probe into a very private area.
other examples of things a person "has", that are privacy interest - what does he have in his possesion/pockets/concealed under his clothes, etc. It's inappropriate for me to inquire into same without cause, iow randomly just because they are walking down the street, like I could randomly inquire about their warrants given if I knew their name/dob and saw them walking down the street.
other examples of things a person "has" - they may have a political belief, religious belief/membership, etc. that is again none of my damn business, except in certain rare circs, but certainy not randomly when I see them walk down the street, etc.
There are all sorts of things like this, whether it's an object in a pocket, a condition, etc. that a person HAS that certainly should not be a target of random police (or anybody else's) inquiry just because you are walking down the street, or filming the cops, or standing on the street corner, or driving by, etc.
"having" a warrant is distinguishable from these, and is not a privacy interest, CERTAINLY not a privacy interest FROM law enforcement, who is tasked with serving warrants . A warrant is not a thing that one chooses to "possess" and keep private, like the contents of one's pockets, it;'s not a sacred private belief, it's not a medical condition, etc.
those things a person "has" of course should be protected from random police inquiry. No libertarian or anybody who has ANY respect for privacy could argue otherwise.
"having a warrant" is not like these things. What "having" a warrant means is that a judge, etc. has reviewed a complaint against a person made under oath etc. and found that there is probable cause to arrest, arrest being a way to formally advise a person of charges, get him an attorney if he wants one, and start the wheels of justice rolling so that justice/redress can be obtained for a victim/society after a criminal act. or it means that the person skipped out on sentencing or incarceration after conviction, or in some cases skipped out on responding to a summons etc. etc.
these are not private things a person "has" in the respect of those mentioned above.
If one describes it then not as a Person having a warrant, but as a Person against whom a warrant has been issued by a Judge having jurisdiction, it is more clear that there need be no indicia of suspicion to check on this.
A warrant is issued because a person CHOSE to ignore lawful process/obligation (like showing up at a court date, or going to an anger management class as a result of a conviction for assault) or because a person was found by an impartial third party (a judge) to have sufficient evidence brought against them such that it is probable that they committed the relevant crime. Among other things, considering it a privacy a interest does a disservice to society and to the victim of the crime. A warrant is not a thing like what a person places in their pocket or other private place, or like any of the above mentioned things that trigger privacy.
It's an official document, official process issued against a person by a member of the criminal justice system, and NEEDING prompt attention for the sake of justice.
NOT making this info OPEN knowledge to law enforcement would be absurd. It would be beyond absurd to make it a privacy interest of person X, that a govt. authority has found probable cause that they committed a crime and wants them brought before a court, to in any way conceal that info from a person (a leo) who is TASKED with executing that warrant.
It would be insane to issue the warrant and ask law enforcement to execute it (and again, warrants have that language "to any peace officer ... etc.) but then require them to have some indicia of suspicion about a person before inquiring into whether such an instrument has been created (the warrant) regarding that person.
It would be even more absurd to believe that whether or not an OBJECT, a car, has been reported stolen, isn't something an officer could randomly inquire into by running a license plate for warrants. What possible privacy interest does an OBJECT (whether or not occupied) have to impede law enforcement from knowledge that some person who lawfully owns it has been unlawfully deprived of it by a criminal, and to that would impede law enforcement in returning the stolen property to its lawful owner?
So, sorry, but this idea that cops should need an indicia of suspicion in these cases is insane. Warrants are not like the other things mentioned, for reasons explained above. I don't care if you are filming the police (constitutionally protected activity that I have engaged in), walking down the sidewalk, driving on by, or not even within eyesight of a LEO. *if* they already know your name, there is no invasion of your privacy in any way, shape or form, for the LEO to check if any judge has found that justice requires you be brought before a court either because there is probable cause you victimized somebody or there is probable cause you chose to ignore an order of a competent court (like an order to appear, etc.)