Your analogy of a chimera is a poor one because Facebook doesn't produce content, it is a vehicle for it.

If I read the article correctly, I could make a manifestly unlawful comment in this textbox by saying something libelous about you and presumably make ycombinator liable for a fine because you're a German citizen. What's more, under the law the burden of proof of the libel is placed on ycombinator, not you, or even myself who produced the content in the first place. Incredible.