People seem to think social media is akin to private communications where it's more akin to the public square. Making your IG/FB/whatever profile private doesn't change that.
In NYC for example, there's been a large uptick in teen shootings, many adjacent to schools, and a lot of it involves the idiots posting on social media before & after. One tool could be simply scraping social media for these postings. Another alternate, pre-internet tool was stop&frisk.
While you have a constitutional right to not be searched without consent/probably cause, you do not have a constitutional right to spouting off in the public square without consequence. What you say publicly can & will be used against you in the court of law.
Putting out an IG post of yourself with illegal guns or inciting a shooting is no more private than printing out posters of the same and putting them up around the neighborhood.
If someone tells you something in private in a public square in a way that nobody else in the public square can hear it, like lowering the volume of their voice so nobody else can hear, then it is possible to discuss in private in a public setting. There is no obligation to immediately share that private information with the entire public square just because the public square was used. This isn't some FOSS with a licensing agreement that says it must be made public.
You can use the features of a social platform to share with a chosen group of people while not allowing the entirety of the platform access. That's what private means. Not respecting that for sake of "it's a public platform" is just that person being a dick. Whether that's you holding this opinion or a scrapper justifying their manner if not respecting the poster's intent, it's all people with utter lack of respect. It's an AB conversation, and you're trying to be C. We've already indicated you're not the intended audience by setting to private. You doing everything you can to get around that is, again, you being a dick
Having public conversations and having cops insert themselves is.. actually really well established case law. Yes the cops can listen in when you have no expectation of privacy.
We don't want cops having and abusing backdoors but "playing the game" is perfectly legit. The cops do not owe you some sense of playing gently.
I'm not sure this is the sentence you meant. Of course anybody can listen in when you have no expectation of privacy. Without a court ordered search warrant, they can't listen in when you do have expectation of privacy.