Unfortunately there is no technical details on those systems.

Do anybody know about their level of sophistication?

Do they mostly make use of "open source" tech you would hear about on HN, or those organizations can actually afford to develop their own tech stack?

Anyone knows if this is related to matrix.org ? Or totally unrelated?

Following up, we at Matrix.org have put out a blog post to clarify that this is unrelated: https://matrix.org/blog/2024/12/unrelated-cybercriminal-netw...

Grateful to NL Times who included this line in their article: "The investigation did not spotlight the similarly-named Matrix open source communication protocol." https://nltimes.nl/2024/12/03/dutch-french-police-take-matri...

Of course, we are staying tuned as more information becomes available.

Totally unrelated. I guess there's a chance that the service might have been built using the Matrix protocol, but we're unaware of it if so - and the app in question doesn't look like any Matrix client I recognise. Unfortunately this looks to be a particularly unfortunate namespace collision.

The takedown site makes it a bit clearer: https://www.operation-passionflower.com/