Threema messages of Marian Kočner, a contorversial Slovak businessman who allegedly ordered a murder of a local journalist, were somehow obtained with the help of Europol. [0]
The part of his trial where a security expert explained how the police got the messages was purposely not made public.
You can think of `i` as a rotation by 90 degrees counterclockwise.
You do it twice and the real number line gets reflected (as if multiplied by -1).
It is what multiplying by i actually does to the complex plane.
If you're interested in this, a while ago, for my personal photo site with image galleries[1], I wrote a fast static site generator in Rust[0], which also supports plugins now.