Yeah, sadly this is a nonstarter for me due to this. Perhaps somebody will expand the idea outside of the Facebook ecosystem, but I'm not about to sign up for Facebook just to give this a try.

I built https://www.giftingproject.org for this. I quit Facebook last year but missed the Buy Nothing group.

When I initially typed in my zipcode and smacked Enter, nothing happened. At all.

I tried again with a neighboring zip, but this time I hesitated for a moment to make sure I entered it right, and the search box did a weird thing where it popped down an expanded city name along with the zip code. I clicked this and THEN smacked enter, and I got a search results page!

Of course there are no results in my area (and no way to tell how large a radius it considers "my area"; should I try again with a zip a few miles away? a few dozen miles away?), but now I know there's a secret-knock to get into the site.

There are similar groups to find on https://freecycle.org/

yeah killed it for me. I use free cycle. It doesn't have the social/bilateral aspect, but I prefer that to zuckerberg.

So essentially you want an open-source, mainstream free to use service that operates at a large scale and doesn't monetize through ads?

Yeah, I wouldn't hold my breath.

You could make a dedicated FB account that you only access from a proxy running on a VM on a cloud provider.

The OP also talks about "open source", you can launch an off-FB group and tell your friends to advertise it on Facebook.

Facebook bans accounts with fake info. They are pretty good at it too. I assume they simply use the contact info the scraped and look for your name in your friends contact lists.

Yeah, the idea is pretty cool, but expecting people to sign up for Facebook for it kinda kills it.