well, there isn’t a ton of point to posting stuff without any location on here, you won’t get any IDs probably, or research grade. You can do private locations, but that also is questionable in value and doesn’t get many IDs. I guess you can post things without any location for your life list, or for your own records. It’s not specifically disallowed or anything. I’ve also used iNat lists with nondescript location description or even plot number to keep track of species lists on private land where i didn’t want to do inaturalist. But in the end, since the data doesn’t go into the database, can’t use fields or annotations, add to species list, etc, i lost interest in doing it and stopped.
There are a lot of different issues mixed in together here. I don’t add things on private property that is posted no trespassing or where i think the landowner doesn’t want it (Vermont is different than most parts of the US where if it’s not posted you can go on the land, though I still am more cautious about how I use iNat) The honest truth is i don’t really love how property law in the US works, but i care about my neighbors and people who own natural habitat here so i tend to obscure for that reason except when landowners don’t want me to (some have asked me not to for various reasons, mostly because it’s a pain for THEM to be able to see it, or they have nature reserves formal or informal on their land and want to show off their biodiversity).
There’s a totally different issue in that some ‘old school’ conservation types think we should just hide everything and only the in-group ‘experts’ should know where it is. I’ve even been told by people in the conservation/management field before that they don’t think ‘ordinary people’ or ‘the public’ should be allowed to view public non- threatened biodiversity data from public lands in the United States. (even though it’s literally legally public info and can be FOIAd to get the info). Without going into a whole long rant here again, i will just say i strongly disagree with that approach and i think it’s a relict of an older method of conservation which has failed badly to prevent the current ongoing biodiversity crisis.
Then there’s just ‘secret spots’. I’ve got some secret spots that i won’t post any location data of any sort for on the Internet and I’ve also had others show me their secret spots which i also didn’t post anywhere. There’s nothing wrong with that. We should have spots like that in the world, and one way or another we always will.