The site that saves 80% on flights is p*ssing airlines off, and they're suing

There's no such thing as a free lunch -- and that goes double on airplanes. Case in point: United Airlines and travel site Orbitz are suing the creator of a website that helps fliers save money by booking "hidden city" fares.

The two businesses filed a $75,000 lawsuit last week against the creator of Skiplagged.com for posing “unfair competition” and encouraging “prohibited forms of travel” that can "intentionally and maliciously" damage operations. Skiplagged indexes “hidden city” destinations, where a flight stops for a connection and the passenger exits early at the connecting city, rather than at the final destination. Skiplagged’s 22-year-old founder, Aktarer Zaman, has said he hasn’t made any profits from the site, which directs users to book tickets through Orbitz.

Though it sounds like a genius travel hack -- sometimes saving up to 80%, according to Zaman's post on Reddit -- “hidden city” booking's frowned upon by businesses. Orbitz, for example, expressly prohibits “hidden city” bookings. And if frequent fliers are caught in the act, carriers can delete their accounts and ban them from flying in future. In addition, luggage may not be loaded off a flight until it's arrived at its final destination, making it even harder for passengers to pull off this trick.

The lawsuit stated that "hidden city" travelers can “cause disruptions” to United’s processes, including the airline’s “ability to estimate head counts” at the airport gate, and even affect “mechanical tweaks, such as variations in the amount of jet fuel needed for each flight". That's a complicated way of saying airlines want to squeeze every last penny out of you, and they'll cite legal and technical tangents to do it.

Zaman is raising money to pay for his lawyers on GoFundMe, where he's made $12,435 out of his $15k goal.