Well, if you have an issue with people knowing you use Plex at all, then… tough luck, because I hate to tell you this, but a media server needs a client and it’s a vanishingly small group of people that will use either Plex or Jellyfin clients and not let Apple, Google, LG, Samsung or whatever other device is running the client software that this is happening.

First:

• not if you install these applications through fdroid or install from source
• not if you block dns queries that report to those servers
• not if you access the service via webURL

but also, it’s not just that they know you use plex or jellyfin, it’s that they know which plex server you use and from what devices you stream from. If, for example, plex decides they want to limit the number of households can stream from a single server (like they’ve already done), all they’d have to do is lock or limit people’s google SSO to that server. They could also report which users are associated with servers engaged in illegal activity when requested, or they could region lock their services or specific media IP’s by request from copyright holders… There’s a ton of abuses that are made possible by even that tiny bit of information they share/collect.

You might not care about it, but a lot of us do. Nobody is trying to convince you to stop using Plex, we’re just trying to explain why we really do not want to use it ourselves

And for the record I do not live in the US and the way their absolutely idiotic copyright loopholes apply here is very much in question. It doesn’t get tested in court much because the times it has been it didn’t go particularly great for copyright holders. Private copying owned media is a right regulated by law here and I will continue to do so.

I have no idea where you live, but plex is an american company. Plex will 100% be forced to comply with copyright takedown requests, and could absolutely penalize you for infringing on american copyright law. Could you be arrested? Maybe not. But there are still a ton of ways you could get fucked because Plex has enshittified their service and has made zero commitments to protecting you or your identity.

we are allowed to back up movies

small thing, but in the US this is technically allowed, but as soon as you format-shift the media (e.g. rip a dvd into a digital format) it is no longer protected. It’s assumed that ‘backing up movies’ is literally ‘duplicate the media in exactly the same format it was originally purchased in’. On top of that, it’s also doubly illegal to then share that media, even as a direct stream via a home server. Idk where you live but I’m actually am not aware of any country who allows for your stated use (unless you’re somewhere without extradition or trade relations with the US like Russia or Cuba, because they don’t give a fuck about US legal claims). Not that it’s commonly prosecuted even in the US, but US companies routinely get takedown requests for that shit and Plex will absolutely throw you under the bus.

That is not a concern, though. Plex is a perfectly legal piece of software.

There are a bunch of reasons why it might be a concern, and only the least of them has to do with the legality of copyright use.

they assume Plex is itself a liability, which it isn’t.

Except plex has already proven themselves willing to ban users based on their use and streaming practices, so it clearly is a liability

It’s weird how corporate copyright assumptions have seeped to the mainstream and people assume that anything you do with your owned media is illegal unless you’re paying somebody.

If you live inside the US (or a state with trade agreements with the US) and are ripping physical media to store on your server and stream digitally, you are absolutely breaking the law. Doubly so if you are sharing that media with others outside your household.

‘It’s not a problem because I have nothing to hide’ <- you are here.

I don’t know that Google gets to log your access in that scenario, Plex is just using their login system

Huh? Google would, at a minimum, know what service is requesting authentication, and plex would know which google user account is being used to authenticate. Maybe they hash that information, but why would anyone trust that? Even if you’re not breaking any laws with what you’re hosting on your plex account, I totally understand why someone might not like the idea of google or plex having data about the identities of users accessing your server and what services are being run from it.