I think most US residents on HN live in a state where blacklisting is illegal. Washington state and New York have labour laws against blacklisting while California has a law against employers preventing previous employees from finding work. I wouldn't be surprised if most states had laws like New York, Washington or California.
Black listing laws are handled at the state level not nationally which makes simply googling them a bit difficult as every state's legal code isn't uploaded and searchable (yet).
