Havatra

BBC has presence and offices in the US, which are held liable for conduct within the US. IANAL, but I imagine legally speaking, you can even hold them liable for content hosted in the US on servers there, perhaps going as far as content that is served to the US. Suing them is just the beginning of the legal process to legally do with that liability as they wish, like removing their servers/access in the US.

deleted by creator

You should contact as many as you can bother, really, regardless of whether they’re the “right” person. It will increase the perceived magnitude of concern, even if just by a little. And every little bit counts.

If it’s the wrong person, ask who you should contact, and keep going!