Do these accept cash, or only ATM cards? (The latter would link your transaction to your bank account, of course.)

What do they give? A printout of a wallet address?

I don’t have a specific suggestion, but here is what comes to mind:

• Violation of human rights and civil liberties in order to gain power over others is always justified with noble-sounding excuses like protecting people and property. The reality does not match the claim.
• Once violated, privacy of information is almost impossible to restore.
• Anything that can be abused to someone’s gain will be abused eventually, if not immediately.
• Relying on a benevolent gatekeeper (even yourself) to prevent abuse of your tech will eventually fail.
• The name V0LT Predator evokes the feeling that it’s something the world needs less of, not more.

Whenever I find myself on a fine line like the one you’re trying to walk, I consider whether I’ll look back on my life and be proud of what projects/causes/changes to the world that I advanced with the time and talents that I have.

Look for an instance with these qualities:

• Does not use Cloudflare or any other large content delivery network. Instances that use thse allow the CDN to monitor everything your read and write on Lemmy, which can reveal a lot about you even if you haven’t used your real name. Cloudflare can then correlate that information with your other browsing habits, and possibly your real identity, because they operate as a middleman for a huge number of popular web sites.
• Maintains a sizable local image cache. Images served from other instances instead of your local one can be abused by remote parties to track what is viewed on Lemmy with your IP address (and sometimes your browser signature). Alternatively, you could block off-site images using a browser extension, but that would mean not getting to see as many pictures.

I think you mean across the internet, but I get your point. You might want to state that in your post.

Its file sharing feature works between any supported devices, including phone-to-phone, and yes, it is intended for connections across a local network.

Why go through someone’s service when you could go direct?

https://kdeconnect.kde.org/download.html

[Citations needed] or it didn’t happen.

I think this mindset is naïve and unrealistic.

People were saying the same thing for decades in response to a small minority warning about government surveillance, often dismissing them with labels like “paranoid”. Eventually, Snowden came along and produced the citations, at extreme risk to himself and his loved ones. It’s an anomaly that they were ever revealed at all.

History is replete with examples of bad stuff going on for ages before irrefutable evidence of it became widely known. In general, if something can be abused to someone’s advantage, it will be, and likely already is.

There’s precious little extra information that a “nefarious” instance can harvest that any basic web scrapper can’t.

You have a point there, but consider also that effective web scraping uses significantly more resources than having the data you want handed to you. Monitoring Lemmy through federation would be much more efficient.

SimpleX has some interesting ideas, but also some shortcomings for people who want a practical messaging service. For example:

• It is funded by venture capital, which calls into question its longevity, and if it does manage to stick around, suggests that it will be leveraged to exploit people once the user base is large enough.
• Its queue servers delete messages if they are not delivered within a certain time frame (21 days by default). Good luck if you take a vacation off-grid for a few weeks.
• No multi-device support. (This means a single account accessed concurrently from multiple independent devices.) The closest it comes is locally tethering a mobile device to a computer.
• Establishing new contacts requires sharing a large link or QR code, which is not always convenient.
• No support for group calls.

I look forward to seeing how its design decisions develop in the coming years, but outside of a few niche use cases, it is not a suitable replacement for Matrix or Signal.