Earlier quoted context omitted.
ffmpeg, VLC and its associated projects are hosted in France. There aren't any US companies for the MAFIAA to shakedown, and if they tried to file for software patent infringement in France, the French courts would tell them to fuck off. So they go after ffmpeg's US-based users/customers instead.
Do French courts enforce patents differently?
France is also a party to the European Patent Convention, which specifically states that programs for computers are not patentable.
https://en.wikipedia.org/wiki/Software_patents_under_the_Eur...
Software patents are mainly a US-only thing.