A subset of those seeking to bully others into labeling their postings with content warnings particularly targets postings featuring commentary on US news, with the implication that news from the US is and should be of no interest to people living anywhere else in the world.
How can what's happening in the US affect me over here in, say, the UK, or up here in, say, Canada? I don't want to hear about it, read about it, know about it.