Update: CBS San Francisco reports that Uber is disabling the illegal app and passengers affected by it will receive a refund. We also have new information from Chris, the driver who alerted the media to the problem, and from a driver named Simon, who said he used the hack after SFO officials blocked Uber cars from going inside the airport.

As recently as May of this year, Uber, Lyft, and other ridesharing companies were still illegally operating at San Francisco Airport. Now one Uber driver tells CBS/KPIX 5 that even the legally permitted drivers are cheating the system to get ahead.

An Uber driver named Chris, who didn't want to be quoted using his last name, says that hacking the app allows drivers to fool the system into making it look like their car is the closest to SFO, and Uber then automatically assigns them the fare.

Chris reached out to SFist to clarify that the "rampant cheating going on each day is limited only to TCP/commercially licensed vehicles." He writes via email to SFist:

The cheating element here is that commercially licensed vehicles are faking their locations by using an additional app for this purpose. So, while two Uber cars might be sitting next to each other in the cell phone parking lot, if one car is cheating, he can falsely set his location to be in the middle of the SFO terminal in ramps (though it is not possible to actually park here) and he will therefore got the next airport order, since the Uber app dispatches orders to the closest available car.

Chris adds: "You are right to point out that un-commercially licensed vehicles are dropping off fares at the airport everyday, but that is a separate issue."

He corrects our original post, which stated that drivers using the illegal app were violating SFO Airport Commission and California Public Utilities Commission (PUC) rules. Uber's TCP/commercially licensed vehicles (classified as a limo service) are permitted to operate at SFO, but UberX vehicles are not unless they have the proper permits (more background below).

He also corrected our figure pulled from the KPIX story that airport rides to SF pull in at least $85: "Only SUV airport orders are $85 and black car airport orders are $65."

An Uber driver named Simon also emailed SFist to shed additional light on how and why this hack got started:

As hard as it is to admit, I am one of those people who hacked the phone to gain fares. Hacking the phone started about 8 months ago when Uber stopped letting drivers stay inside the airport by blocking out the area. My understanding was SFO wasn't too happy with Uber drivers occupying spaces at the parking lot. However, that little change made everything go haywire. Even though Uber sent email to all its drivers reminding them to stay at the cell phone parking lot, it was faster to get a fare if you circled in front of the airport ,so everybody did. It was illegal and dangerous, but it was the only way for anyone to get a fare (actually friend of mine got arrested for driving around there with Uber phone and was fined with $2000 ticket). Soon after that people started hacking their phones (who can blame them because they are just like everybody else who trying to make little bit of money to support themselves). BTW, how they hacked their phone was [to] jailreak [it] and install Uber along with location spoofing software. In the end, if it wasn't for those people at SFO who insisted Uber to block their drivers from going inside the airport, nothing would have happened.

The battle between ridesharing apps and SFO began in 2013 when airport officials started making citizen arrests of drivers not permitted for commercial business. Still, these drivers continued to take fares to and from SFO.

On April 7, according to the San Francisco Business Times, SFO officials issued permit applications to local ridesharing companies, but none applied. The proposed permits would have allowed Uber, Lyft, and the likes to drop-off passengers at the airport, but not pick them up, and charged a fee per trip that's in line with what taxis currently pay.

In May, SFO police wrote up 101 UberX drivers illegally working the airport, SFO Director John Martin told the San Francisco Business Times. Martin sent a letter to CPUC President Michael Peevey demanding it take further action to enforce the rules. In response, Uber, Lyft, and Sidecar issued a letter to San Francisco Mayor Ed Lee claiming that SFO officials refused to meet with them to discuss the permit stipulations. Lee said he’s staying out of it. Read both the ridesharing companies' letter and Lee's statement at TechCrunch.

Read all previous SFist coverage of Uber.