United Airlines

The footage taken inside the airliner shows a man being violently pulled out of his seat and dragged down the aisle as passengers prepared to take off from Chicago to Louisville on Sunday evening.

The airline in question - United - has tweeted an apology for what happened and says it is investigating.

One 50-second clip of the incident on Twitter was re-tweeted 16,000 times since it was posted that day.

Olivier Beg, a 19-year-old security researcher from the Netherlands, has earned 1 Million air miles from United Airlines for finding around 20 security vulnerabilities in the software systems of the airline.

Last year, Chicago-based 'United Airlines' launched a bug bounty program to invite security researchers and bug hunters for finding and reporting security holes in its websites, software, apps and web portals.

Perhaps then it is no surprise that Spirit has the highest complaint rate of any major U.S. airline.

Spirit, a low-fare, high-fees carrier with a clientele of mostly leisure travelers, had by far the worst on-time performance in June among 14 airlines tracked in a government report. Only 49.9 percent of its flights arrived within 15 minutes of schedule, which is the government's definition of being on time.