This poster clearly has some sort of vendetta against Lemmy and/or its creators with the comments on politics, etc.
Reddit takes your activity and packages/sells your data to advertisers. Lemmy does not. To say Lemmy is worse than Reddit for privacy is just not true.
On lemmy (and mastodon, kbin, etc) it seems like it's extremely easy for a third party company to datamine everyone's data, even deleted ones. Federated software is terrible for privacy because it creates hundreds of backups to the federated instances. Any one of those instances can decide not to actually delete anything when requested.
Just like on reddit, treat everything here as public. Do not post things that you want to be private to either site; this goes for literally any website you don't own.
It reads like someone has just discovered that if you toss out public data on the public internet via federation it becomes public and out of your direct control.
That's how all federated services basically work: once it is relayed to someone else's server, there's essentially nothing you can do to force deletion.
Easy example: if you send me an email, but delete it from your sent messages, did you delete the message I got?
Lemmy is meant to be a public website with public content. And in general, that post is either very uninformed or in bad-faith as most of these things are unavoidable in federation or even protect former users from impersonation.
Any claims made about privacy on a social media site, especially ones run by private companies or individuals, should be met with extreme skepticism. The reality of privacy on the internet is that it is not something you can get by picking a different service, it is something you must constantly maintain with vigilance and an up to date understanding of infosec practices.
Sites like these cannot be private by design. Their whole purpose is making data publicly avaliable.
If you want none of data here linked to you, register on an instance that does not require email and don't use your nickname, that's all there is to it.
Privacy is tricky. I've seen complaints that anything you post stays forever. But honestly, is that what you consider private?
Do you think it's more private to make and delete posts than to just use a VPN and an anonymous account? Having the ability to delete posts doesn't help your privacy at all. At least there's no advertisers being sold all our data.
And the chat thing really needs fixed. But for quick one-off messages, it's fine. Maybe just too exchange secured accounts
Everything you post on lemmy is intended to be public, so there really isn't a point to it having privacy features like encryption. There is the one sticking point of dms being readable by the relevant instance admins, perhaps that will change at some point, but for now lemmy supports attaching a matrix handle to your account for secure messaging.
That said, something the underlying protocol (ActivityPub) does have, are standards for both editing and deleting your own posts. It will be quite possible to have everything or anything you've put out there changed or removed, much like on reddit. The action will propagate to all federated instances.
Also I'm not sure what you mean by there being no history deletion in matrix? I run a node, and purging a room, or an entire account, is absolutely possible. You can even set a node up to only retain data for a certain amount of time. Or are you referring to the fact that you can't make another node that has the history for people you've talked to on it, delete it?
There ActivityPub has matrix beat, if you delete your comment, any instances it was visible on (unless they defederated since) will also delete it.
Privacy enthusiast and software developer here. I would not consider that post an "article". It is an alarmist mess.
Point 3 is so vague as to be useless, and its link doesn't clarify at all, so I won't try to address it.
To points 1, 2, & 4:
As far as I can tell, Lemmy does in fact federate deletes. If those deletes are not being honored, then the problem lies not in the Lemmy network, but in one implementation of it, which can be fixed.
If Lemmy's code is hiding posts instead of deleting them, you could submit a change request to address it. Chances are there's another way to accomplish whatever goal is behind the current behavior.
You could also write (if you're a developer) or sponsor (if you aren't) an alternative implementation. Make yours fully and immediately delete, and make it otherwise good, and it could become the dominant software for running Lemmy instances.
If your concern is with the Lemmy developers' ethical positions, you wouldn't be the first, but distancing yourself from them doesn't require abandoning the network. You can simply use an alternative implementation (e.g. Kbin) or join communities that aren't hosted on lemmy.ml. That's one of the great benefits of the network: no single person or server controls it.
I strongly believe that public discourse is healthier on decentralized communication services. For link sharing and conversation, I don't know of another platform that comes close to Lemmy's chances of success. It has flaws, but nothing that can't be fixed over time. And we need one now. The important thing is to get people using it; build the communities. That will make the time investment required to improve it worthwhile.
Regarding privacy:
Let's try to remember that it is not possible to revoke something that has been made public, on any platform. Bots exist. Caches exist. Web crawlers. Intelligence agencies. Archives. Screen shots. Backups. The closest we can come is to encourage people on the network to honor deletes, and hope the remaining copies don't turn up at an embarrassing moment.
And as always (even before the internet), it's probably a good idea to think about our words before publishing them to the public.
Seriously. If you are posting private information on any forum, you are doing it wrong. It doesn't matter if that is Twitter, a Lemmy, or a BBS. If it is private information, don't post it publicly.
Also note with private information, assume someone will comb through all of your posts. Is the sum total of what you have released enough to ID you? One post may say what state you live in, another might say you find it funny your city is a name of a founding father, another might say you live a half mile from school and walk, etc, etc. Don't release data points that when summed can ID you.
They can; but remember you are posting public information on a public forum. The privacy features are all about what you type or don't type. Never type private information into a public forum.