Since the onset of the COVID-19 pandemic last year, and the introduction of face mask-wearing mandates aboard flights, the number of naughty passengers has increased exponentially.

But this much?

The airlines and the Federal Aviation Administration have been cracking down on unruly behavior, to the point where more than 4,000 fliers have been banned in the last year according to CBS News .

In fact, some passengers are facing fines of up to $30,000 for their activities on some flights.

Here’s a breakdown of the top 10 U.S. carriers and the number of passengers they’ve banned:

– Alaska: 538 since May 11, 2020

– Allegiant: 15 since July 2, 2020

– American: does not report

– Delta: more than 1,200 since May 4, 2020

– Frontier: 830 since May 8, 2020

– Hawaiian: 106 since May 8, 2020

– JetBlue: 140 since May 4, 2020

– Spirit: 604 since May 11, 2020

– Southwest: does not report

– United: 750 since May 4, 2020

That’s 4,183 without two major airlines reporting.

And we haven’t even talked about the FAA fines yet. The agency has its sights set on four passengers, including one that owes more than $30,000 in penalties.

CBS noted that this includes a February 7 JetBlue flight headed to New York that had to return to the Dominican Republic after a passenger refused to wear a face mask after being asked by flight attendants to wear one. The passenger threw an empty alcohol bottle and food, cursed at crew members, grabbed one flight attendant and hit another and drank alcohol that wasn't served to her.

At least one airline said it isn’t as bad as it seems.

"With the federal mandate for air travel (including airports), and our face covering policy designed to ensure to the greatest degree that issues are addressed on the ground and potential violators do not board an aircraft, we find that the great majority comply," says a statement from Allegiant. "For the most part, those few who may need a reminder in flight also comply."