ABC News' Elisabeth Leamy and Vanessa Weber report:
Nearly 45 million Americans move every year, according to the U.S. Census Bureau. That's 14 percent of the population on the go - and in danger of being taken advantage of by movers.
One consumer got revenge by videotaping movers behaving badly and taking the evidence to court.
Caught on tape were movers delivering broken belongings. The items were delivered late and left outside.
The original estimate for the job was $7,000, but the moving company, Golden Hand of Colorado, later demanded $25,000.
This is not the only case.
Cameron Almond and Vanessa Stockmar hired the same moving company. They had a similar experience: a lowball estimate of about $3,000, followed by a demand for nearly $10,000.
"It was crazy," Stockmar said. "We slept on the wood floor. We had nothing."
"I actually told him, 'You're not even the company that I had talked to in the first place to make this deal,'" Almond said. "And he said, 'Well, I'm the company that you need to be talk[ing] to now because I have your stuff.'"
It's the latest problem in the moving industry. Customers book their moves online, not realizing they're dealing with sketchy moving brokers who provide unrealistically low estimates, then sell the leads to actual movers - like Golden Hand - that jack up the price and hold people's goods hostage until they pay, authorities say.
Almond and Stockmar went undercover for the FBI to a warehouse and found their things and lots of other items belonging to other customers. Their stealth mission helped the feds close the case.
A non-profit group called Move Rescue, started by legitimate movers, helped Almond and Stockmar retrieve their belongings.
"We're able to use our network of Mayflower agencies across the country who will pick up those goods, that have oftentimes been abandoned in storage, and deliver them to the customer free of charge," Melissa Sullivan of Move Rescue told "Good Morning America."
The government indicted Golden Hand's owner, Yaron "Roni" Levin, on 55 counts, including extortion and theft.
The attorney for the company's owner said Levin was "a small businessman who feels that he did his moving work the best he could under confusing regulations and difficult circumstances and deadlines."
So how can customers separate the good movers from the bad?
It's simple. Never, ever hire a mover that will only give you an estimate by phone or mail.
Insist on using a moving company that will come to your home and look at your belongings before giving you an estimate. When they do, insist on a binding estimate that is guaranteed not to exceed a certain price.
Click HERE for more tips about what to be wary of when you're hiring movers.