What is the sentiment of this news? Please choose an answer from {strong negative/moderately negative/mildly negative/neutral/mildly positive/moderately positive/strong positive}.

A group of workers at an Amazon air freight hub in San Bernardino that has been pushing for a $5-per-hour pay increase and more robust safety measures accused the e-commerce giant of unfair labor practices in a Thursday filing with the National Labor Relations Board.
moderately negative