Yep, everyone can see it. If you want, you can actually host your own Lemmy server dedicated to spandex hamsters.

I just found this neat little graph if you want a visual aid: https://imgur.com/a/uyoYySY

Data syncs between all the servers.

All the servers are linked, sending and receiving data to each other. If someone makes an account, post, comment, or community; it gets sent to every other server that’s running Lemmy. This allows someone from different servers to interact with each other.

This comment I’m making is actually an example of this. I am from lemmy.world, but you are from lemmy.ca as shown from our usernames. Because both our servers are talking to each other, I am allowed to see and interact with you.

Posts from lemmy.ca should be able to show up for everyone else, and lemmy.world is not like r/all, they both see the same stuff. Although it’s possible to only view data from your own server by selecting “local” at the top of the page.

It’s like usenet if you have experience with that.

To be fair, the way it’s currently implemented is not the most user friendly. By default, only local posts from your server show up. You need to manually select “all” or “subscribed” to view posts outside of your server. It also makes it hard for users to choose which server to make an account on. Some servers even hide some stuff like downvotes, which is what Beehaw does.

Password protect your services, set up your web server correctly, use cloudflare for some extra security against stuff like DDoS/DoS attacks. Also less is more, do not expose what you don’t need to expose.

There is always inherent risk with opening up your stuff to the world wide web.

Some stuff you can’t even secure yourself; some services just have bad security practices. The only way to fix them would be to wait for an update or submit a pull request.

Eweka + NZBGeek Eweka has a massive sale, but I can’t find it because it’s on a privated Reddit sub.