The FAA has issued millions of dollars in fines against "unruly passengers" since 2020. J. David Ake/Getty ImagesThe FAA has fined 'unruly passengers' over $20 million since 2020.The number of passengers misbehaving on airlines spiked during the height of the pandemic.The FAA told Business Insider it has a "zero-tolerance policy toward unruly passengers."Misbehaving airline passengers are paying a steep price.Data shared by the Federal Aviation Administration showed that it has fined "unruly passengers" over $20.9 million since the COVID-19 pandemic began in 2020.