United Continental Holdings (UAL) is caught up in a public relations hurricane after a video of a passenger being dragged off a United Airlines flight from Chicago went viral and the company botched several attempts at damage control. The passenger was forcefully removed for refusing to give up his seat on an overbooked flight after he was chosen to be "involuntarily deplaned." But this is not the first time that United has made news for ungraciously handling a situation that involved passengers being involuntarily bumped from seats they had bought and paid for.

In 2013, Ewalt Shatz, a 90-year old Pearl Harbor survivor and World War II veteran was bumped off his flight to Hawaii when he was en route to a ceremony to honor veterans, reports CNN.

"I thought that they just overbooked the deal and they were trying to get rid of a couple of customers, because somebody had my seat, and that's what made me mad, because I paid for that seat, and somebody else was sitting in it," Shatz told CNN. Shatz was booked on another flight for eight hours later. The airlines however responded that it had to reduce passenger count to accommodate more fuel due to impending bad weather. On this particular flight, the report said United removed 41 other passengers.

Not only that, overbooking could also mean that passengers do not get some of the luxuries that they paid for, as one investment manager found out. The Los Angeles Times reported that 59-year old Geoff Fearns paid $1,000 for a full fare first class ticket to fly from Hawaii to LA after a conference. United had other plans and asked him to deplane after he had settled into his seat on the plane to make way for “someone more important” and threatened to put him in handcuffs if he didn’t comply. After some arguing, United found another way by relegating him to the economy class.

(See also: The Biggest Airline PR Disasters of All Time)

Overbooking Policies

But United is certainly not alone in overbooking, and it is not even the worst offender. Data from the U.S. Department of Transportation shows that in 2016, more than 475,000 people were denied boarding on oversold flights. Nearly 8.5% of them — more than 40,000 people — were denied boarding involuntarily, while the rest gave up their seats willingly. For United, those numbers stand at 62,895 voluntary denied boarding and 3,765 people who were involuntarily barred from a flight. That puts United in the middle of the pack with Delta the worst in voluntary denied boardings and Southwest the worst in involuntary denied boardings.

According to the Department of Transportation, when airlines overbook a flight, they are allowed to ask passengers to voluntarily give up their seats or be bumped off involuntarily. The Department of Transportation does not prescribe a fair compensation to passengers voluntarily getting off but urges these customers to ask questions about the alternatives they have.

(Read More: Did United Have the Right to Force That Guy off the Plane?)

For passengers who get kicked off involuntarily, the Department of Transportation mandates that they be given a written statement describing their rights and an explanation of the airlines’ policy in selecting which passengers get to stay on an oversold flight. Such passengers may also be eligible for denied boarding claims prescribed by the department.

For example, if the alternative arrangement gets the passenger to his destination within an hour of the original arrival, no compensation is paid out; however, a delay of up to two hours could entitle the passenger to up to 200% of the one way fare increasing with the delay time. Having said that, the ultimate decision on who gets deplaned rests with the airline itself.

“Airlines set their own "boarding priorities" -- the order in which they will bump different categories of passengers in an oversale situation. When a flight is oversold and there are not enough volunteers, some airlines bump passengers with the lowest fares first. Others bump the last passengers to check in,” the DoT says.

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