From matrix.org:

An unrelated cybercriminal network named MATRIX was taken down

The Matrix.org Foundation has been made aware that an international investigative operation took down a service called MATRIX which was used by a cybercriminal network, which has no relationship with the Matrix.org Foundation or the Matrix protocol itself.

The takedown site has a Matrix-the-movie branding, which is a probable source of confusion. The app showcased doesn’t look like any of the Matrix clients we’re aware of.

https://matrix.org/blog/2024/12/unrelated-cybercriminal-network-taken-down/