It's Americanized because most other countries on Earth don't enshrine it as a principle at any level, whether private or public. The topic is hairy in the US because the government is actually obligated to care, so there are various grey areas when it comes to the interaction between US laws/constitution/government/private businesses.

Compare this to say the UK where neither corporations nor the government enshrine free speech, so these estuaries don't exist.