Sprinkled throughout the typical travel days are the cranky flight attendants and passengers, intermittent in-flight wi-fi, and long waits on the tarmac.

But even in these days of chronically late flights, unremarkable customer service, and excessive fees, there are still incidents that are noteworthy—and not in a good way.

What Happens When No One Volunteers

Anyone who has flown in the past several years has likely encountered this classic game of trying to coax passengers to give up their seats for a voucher. Airlines often overbook their flights and when everyone shows up the staff begins, like an auctioneer, offering $200, $400, how about $600—anyone?— to anyone willing to forgo this flight for another one.

What happens when no one steps up? This week, video was posted showing security forcibly removing a man from an overbooked United Airlines flight. The fallout has been swift and unrelenting even as United Airlines CEO apologized and said the company will work “with a sense of urgency” to review the matter.

The Ultimate Exit Interview

JetBlue flight attendant Steven Slater made perhaps the most famous exit ever from a job. After an altercation with an alleged abusive passenger on a flight between Pittsburgh and New York City, Slater took to the plane’s public address system to air his grievances. He then publicly quit his job, grabbed two beers, deployed the evacuation slide on the plane, and bailed from the scene.

Computer Bugs

Several airlines have dealt with widespread computer outages in recent months that have led to hundreds of grounded flights, stranding travelers and causing general chaos. Southwest Airlines and United have suffered computer glitches that affected flights.

Delta has had not one, but two major computer outages over a six-month period: one in August 2016 and another in January. The fallout from Delta’s latest glitch was compounded by challenges among all airlines to comply with travel restrictions enacted by President Donald Trump’s executive order to block travel from seven predominantly Muslim countries.

Diet Coke As a Weapon

An alleged incident between a flight attendant and a Muslim-American woman prompted United Airlines to publicly apologize and open an investigation. The 2015 incident on a Shuttle America flight centered on a flight attendant’s alleged refusal to hand Tahera Ahmad, a Muslim American chaplain at Northwestern University, an unopened can of Diet Coke.

Ahmad, who was wearing a hijab on the flight from Chicago to Washington, D.C., says she protested when a passenger next to her received a can of beer. The situation soon escalated when another passenger upon hearing her request allegedly yelled, “You Muslim, you need to shut the … up,” and said that “You know you would use it as a weapon.”

It All Started With a Guitar

In the era of social media, customers often take to Twitter or Facebook to spread their tales of airline traveling woe. Musician Dave Carroll used music—three catchy songs in all—to share his account in 2008 during a trip on a United Airlines flight that resulted in a broken guitar and the company’s subsequent response.

The song “United Breaks Guitars” became a viral hit on YouTube and iTunes when it was released in July 2009.