United Airlines
A United Airlines Boeing 747-400 lands at San Francisco International Airport, April 16, 2015. Reuters

Airline travel can be quite bothersome, instead of being just a quick way to get from one place to another. The troubles could be anything from paying extra for your luggage, to waiting in long security lines and ending with jostling for armrest space on the not-so-comfortable seats after struggling to to squeeze hand baggage into the overhead storage compartments.

As if it needed to get worse, some airlines put their worst foot forward and exhibit customer service that can leaves a lot to be desired. And in that respect, United Airlines has been making news for all the wrong reasons. Here are some examples.

1. A man was violently dragged out from a United Airlines flight April 9 by aviation police officials at Chicago’s O'Hare international airport. The video, recorded by other passengers on the plane, created outrage on social media. The incident was said to have happened because the flight was overbooked and none of the passengers wanted to give up their seats willingly. United CEO Oscar Munoz called the passenger "disruptive and belligerent" in a letter he wrote to his employees after the incident, according to CNBC.

2. In 2008, Musician Dave Carroll expressed his discontent on a United Airlines flight with the help of music. He created three catchy songs that spoke of his experience on the flight, which resulted in a broken guitar and the authorities' response to the incident. The song was called "United Breaks Guitars" and it was a huge hit on social media, garnered lots of views on YouTube and iTunes, following its release in July 2009.

3. In 2015, United Airlines was forced to open an investigation and apologize publicly after an incident on a Shuttle America flight that involved a flight attendant and a Muslim woman, Tahera Ahmad, who claimed an attendant refused to give her an unopened can of Diet Coke. Ahmad claimed the attendant gave a beer can to a passenger beside her, but refused to do give her a Coke can. The incident escalated when another passenger who heard her request allegedly yelled "You Muslim, you need to shut the … up," and said "You know you would use it as a weapon."

4. In 2012, Annie and Perry Klebahn, parents of a 10-year-old girl, Phoebe, accused United Airlines of losing their daughter while she was flying alone from San Francisco to Traverse City, Michigan, via Chicago in June. According to the parents, no staff showed any concern to help her get onto her connecting flight in Chicago. Phoebe missed her flight but United did not inform her parents. They wrote a letter to the flight authorities saying it was extremely irresponsible on the part of the airline. United placed Phoebe on a flight four hours later to Traverse City, but her luggage did not fly with her.

"We estimate that we spent around 18 hours collectively on the phones, on hold, trying to track down Phoebe, her bags and our peace of mind," the parents wrote in the letter. "Phoebe never wants to fly United again," the Huffington Post reported.

5. In another incident in 2012, the founder of a group called Paws and Stripes said United Airlines staff not only insulted him at the Dulles airport outside Washington, D.C., but also kicked his service dog twice. A United staffer who said he was scared of dogs kicked the customer's service dog twice.

"[He] kicked her so hard on the rib cage, that she flew into my lap… He said he was afraid of dogs," Jim Staneck, the founder of Paws and Stripes said at the time, Consumerist reported.

Staneck suffered from post-traumatic stress disorder and had difficulty reading the ticket confirmation email on his phone. He asked a United staff for help.

"He said, ‘Just read it’ and I said, ‘Sir I can’t read it,’ and he said, ‘What are you retarded?'" Staneck said. "Prior to this I told him I have a brain injury and PTSD, I’m a disabled vet, this is my second night here; I need help," he added.