My first thought for a substitute that meets your criteria is a private Discord server for each of your particular interests/hobbies, but I’m fairly new to Discord and I never really understood Pinterest. In any sort of situation, if someone who is provided access to non-public info decides to take that info and run, there’s fundamentally nothing to stop them apart from consequences; ex. a general who learned classified military secrets and wanted to sell that info to an enemy state would (ideally) be deterred by punishment from the law. Sure you can muddy the water by distributing information that is incomplete or intentionally partially incorrect, but the user/general still needs to know enough to operate without error.

Long side tangent warning:

Is your concern mostly the data being harvested, or when you say “safe from AI” are you also referring to bot accounts pretending to be real users? If the latter is a concern, I’ll first copy a portion of a Reddit comment of mine from over a couple of years ago (so possibly outdated with tech advancements) when I was involved with hunting bot accounts across that site and was asked about how to protect against bots on NSFW subs:

“I have been trying for a while to figure out a way for subreddits to require users to pass a captcha before posting and/or commenting; however, I haven’t been able to find a way that works and is also easy for the mods to implement. The closest solution that I’ve seen is the verification posts which some NSFW subs require. This is example is copied from the rules for r/VerifiedFeet:

Verification Required: Start Here Posts & Comments Reported as: You MUST include “Verify me” or “Verification” in your post title. Verification steps:

1. ⁠Submit three photos using Reddit’s multiple image uploader. Show your feet with a written verification containing your username, the date, and r/VerifiedFeet. Add a fold to the paper somewhere and hold with your hands or feet. Each photo should be a different angle.

2. ⁠Add “Verify Me” or “Verification” in your post title or it won’t be seen by Mods.

3. ⁠Wait for a verification confirmation comment from the Mods to begin posting in our community.

Instead of requiring the photos to be taken against the user’s feet, perhaps other subreddits could permit it to be against any arbitrary object of the user’s choosing. Seeing as the subs which you mod are all text-based without images, my suggestion is setting those subs to Restricted, creating a new sub for users to post their verification photos, and then whitelisting the users who have done so (as well as whitelisting the users who have already posted and commented to your sub prior to this).”

Since AI has advanced enough that higher end generators can create convincing images of verification photos such as these, one thing that it cannot impersonate yet is meat. As in, you can certainly verify that somebody is a living being if you encounter them in person. Obviously, this is limiting for internet use, but on a legal level it is sometimes required for ID verification.

Or if you’re referring to human users posting AI-generated content, either knowingly or unknowingly, there’s not any way to fight that apart from setting rules against it and educating the user base.