Maybe they could arrest employees on a visit to the EU? Maybe you could even get arrested at home due to extradition agreements? Or get assets in the EU frozen or seized? But that is all pure speculation, I have no idea what actually can and can not be done or what is likely to happen.

They are perhaps owned by media organisations that do in some way do business with the EU even if those specific outlets do not.

as soon as some of some assets pass through entities in the EU (or even, entities on wich the EU can apply pressure), they would be seized.