Valerie Szybala thought she made the right choice when she accepted United Airlines' offer to deliver her delayed luggage.

This was in the last week of 2022,???.?????.??? ????.????.????? when bad weather and operations failures canceled thousands of flights, most of them on Southwest Airlines. Szybala had just landed at Reagan National Airport in Washington, D.C., when the United app notified her that the bag wasn't on her flight from Chicago. It seemed easier to let the airline bring the bag, packed with souvenirs from a long vacation, directly to her home.

After all, she'd put an Apple AirTag in her luggage, letting her track the bag's journey. But Szybala could not have imagined what came next.

"That's where the real chaos began," Szybala told Mashable.

When the tagged bag departed the airport on Dec. 29th, Szybala says, it seemed on course for delivery a few miles away. AirTags are intended to track personal items, such as wallets and car keys, by sending out signals that can be detected by Apple's Find My network. (Privacy experts have been critical of the device's ability to track people without their consent, including victims of domestic violence.)

Szybala's bag never arrived on the 29th. She kept watching it the next day, and it appeared to settle in for the evening at a residential apartment complex.

That's when she started to worry.

Since the Find My network provided her with the bag's location, Szybala decided to go there herself. Thus began a viral Twitter thread on the saga. At time of writing, the first tweet in that thread had been viewed 15.5 million times.

Szybala's experience is a cautionary tale about trusting airlines and their third-party courier services to return delayed or lost luggage — and why a tracking device might just be the leverage travelers need to hold major corporations accountable for their practices.

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When Szybala arrived at the apartment complex, she saw and photographed emptied suitcases near a dumpster. Panic set in. A text chat with a United customer service representative, via the carrier's app, left Szybala feeling "gaslit."

A screenshot of the exchange shows Szybala pleading with the rep for clarity about why her AirTag indicated the bag was at an apartment complex, not a secure distribution center as the rep insisted. The rep, whom Szybala couldn't confirm was human, replied: "Calm down you bag is at the delivery service."

"When I thought that there was someone stealing bags, and maybe emptying them out, is when I was like, 'I need to take action,'" she said.

Szybala kept returning to the complex with the hope of finding her bag, with no luck. At one point, she watched the bag travel to a McDonald's.

"ANOTHER MAJOR UPDATE: My luggage AirTag has left McDonalds and returned to the apartment complex where it is being held hostage!" Szybala wrote on Twitter.

As her tweets circulated, Szybala received DMs from people with similar horror stories and inside information about how luggage is supposed to be handled. Several pointed her to a Houston-based company, Wheres My Suitcase (sic), used by multiple airlines. Its Yelp page is covered in bad reviews.

Szybala was told by United that she could track her bag on wheresmysuitcase.com, but the website never updated the location of her belongings. She had no way to reach the courier service directly.

Szybala also says one industry insider told her that standard procedure is to bring luggage back to the distribution center if it can't be delivered. What the suitcase in question was doing at an apartment building is still unknown.

On her fourth trip to the complex, Szybala received a text from the courier service. The delivery person said they'd delivered the bag to the wrong person in Virginia, and had to retrieve it. Given the AirTag details, Szybala doesn't believe that story — but she did get her bag back on Jan. 2, three days after it went missing.

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"It doesn't seem above board to me," she said.

When Mashable asked United Airlines for comment on the situation, the carrier said in an email: "We are working with our baggage delivery vendor to understand the details of this situation."

United Airlines sent an additional update following publication of this story: "We've been in touch with this customer to discuss this situation and confirm she has received her luggage. The service our baggage delivery vendor provided does not meet our standards and we are investigating what happened to lead to this service failure."

Szybala wrote on Twitter that travelers should consider using a tracking device in their luggage. Without it — and the viral Twitter thread — Szybala said she probably wouldn't have her bag.

Indeed, the holiday travel nightmare appears to have convinced other fliers to do the same. NBC News' Scott Budman reported Monday that Apple AirTags have become a best-selling item on Amazon in recent days.

Szybala also recommended that travelers photograph or inventory their belongings before flying, and that they opt to pick up delayed or lost bags from the airport rather than have them delivered. Still, she believes that United ultimately bears responsibility for what happens to travelers' luggage, and how fliers are treated by the company when that happens.

"Obviously this is not going to change everything United does, but certainly getting all of this attention — the negative press — is kind of the only thing that might prompt them to evaluate some of these practices," Szybala said.

UPDATE: Jan. 2, 2023, 3:55 p.m. PST This story was updated with a new statement from United Airlines.