Delta Air Lines has banned more than 800 passengers for not wearing masks when flying during pandemic or harassing lawmakers

• Delta Air Lines has banned "north of 800" passengers for mask non-compliance.
• Additional passengers have been banned following Wednesday's Capitol riots but executives wouldn't say how many.
• Delta has also banned passengers who harassed Utah Senator Mitt Romney on a flight from Salt Lake City to Washington.

Airlines have been warning flyers since the spring that not wearing a mask could result in a ban but that hasn't stopped rule-breakers from trying.

Delta Air Lines announced during its fourth-quarter earnings call that "north of 800" passengers have been banned since the policy was enacted in May 2020. A Delta spokesperson confirmed to Insider that the official number is 880 passengers.

Additional passengers were banned in the wake of Wednesday's riots at the US Capitol Building. "Not a huge number, but a number," one executive said when asked how just how many were barred from the airline.

Also on a banned list are six passengers who harassed Utah Senator Mitt Romney on a flight from Salt Lake City to Washington, DC on January 5. Supporters of President Donald Trump accosted Romney in the airport terminal and continued the harassment onto the plane with shouts of "traitor" during the flight, with some also breaking the mask rule, according to the airline.

Those banned under the mask policy may be allowed to fly Delta again once the rule is no longer in place with no chance of appeal until then, a spokesperson told Insider. But those who have committed additional offenses may be banned longer, at the airline's discretion.

The Capitol riots saw multiple airlines report disturbances on flights to and from Washington. An American Airlines flight turned into an airborne Trump rally as red-capped passengers began chanting "USA" and disobeying the mask rule, prompting the flight crew to threaten a diversion to Kansas to restore order.

An Alaska Airlines flight from Washington, DC to Seattle following riots also saw 14 passengers banned for violating the airline's mask policies. An airline spokesperson told Insider that the passengers exhibited "non-mask compliant," "rowdy," and "argumentative" behavior.

Airlines attribute mask-wearing policies and the effectiveness of high-efficiency particulate air filtration systems to the low onboard transmission rate of COVID-19. Exceptions to the mask rule are only made for actively eating and drinking while onboard.

Read more: Airline workers have lower rates of COVID-19 than the general population - and airline CEOs say it's proof that flying is safe

One of the most notable banned passengers is Robert O'Neill, the former US Navy SEAL that claims to have killed Osama bin Laden during the 2011 raid in Abbottabad, Pakistan. Delta added O'Neill to the list after he tweeted about openly disobeying the requirement while sitting in first class.

Delta flyers seeking a medical exemption to the mask rule must undergo a virtual screening with a medical professional.

"Customers with underlying conditions that explicitly prevent the wearing of a face covering or mask are strongly encouraged to reconsider travel or should be prepared to complete a 'Clearance-to-Fly' process prior to departure at the airport," the airline's website states. "If you require this exemption, please arrive early to complete the process during check-in and avoid missing your flight - this process can take over one hour."

Delta is also the last major US airline to block middle seats onboard its aircraft after Alaska abandoned the practice after January 6 and others began filling their planes towards the end of 2020.

Delta executives told analysts during Thursday's earnings call that no decision has been made yet on whether that policy will be continued after March.