DALLAS ( TheStreet) -- Uncontrolled sprees by malfunctioning computers, one at a brokerage firm and one at an airline, made news this week. But the airline's problem was small enough to fix. In fact, Southwest > ( LCC) , provided a positive outcome for its customers, making them whole and also issuing $150 vouchers to each of them in what S&P Capital IQ analyst Jim Corridore said was likely a "very minor" financial event. By contrast, Knight Capital Group ( KCG) lost $270 million after taxes, its shares have fallen 69% this month, and its CEO, fighting to save the company, had to sell 73% of it at a cut-rate price "Our problem was much more contained," said Southwest spokesman Brad Hawkins. Knight Capital's problem occurred on Wednesday, Aug. 1, when a software glitch led to a series of unintended trades that left the company holding $4.5 billion of unwanted securities. Two days later, a computer glitch that followed a discounted ticket promotion by Southwest meant that customers who tried to book single tickets somehow found themselves buying multiple tickets -- at times, as many as 20 -- and paying for each of them. "The problem with computer software is that as it gets better and better, the bugs become more difficult," said Eric Scott Hunsader, founder and CEO of trading software and technology firm Nanex. "With well-developed software, the only bugs left are the impossible ones." Imperial Capital airline analyst Bob McAdoo said both glitches led to unrestrained computer behavior. In the case of Southwest, "money was sucked out of some people's bank accounts," McAdoo said. "I have never seen anything like that before. If you bought a ticket with a credit card, it would buy more and more tickets automatically until the credit card maxed out." Southwest's problem occurred between 4 p.m. and 5 p.m. Friday, Aug. 3, shortly after the carrier decided to thank all of its 3 million Facebook friends by offering half-price tickets on select fares. Many of those friends -- Hawkins would not say how many -- responded to the promotion, leading to a technical glitch that was apparently related to the overwhelming response.
Once they became glitch victims, some Southwest "friends" were posting stories on Facebook about the distress that resulted from finding multiple charges for single flights on the credit and debit cards. Some said they spent hours on the phone on Friday or Saturday, waiting to correct their problems. But over the weekend Southwest moved to respond so that by Sunday it had issued refunds to all of the customers involved. "The big currency for us is the trust of our customers," Hawkins said. "We worked hard to let them know we were fixing the problem. We took care of all erroneous charges and fees, and also sent an apology email with news of a $150 voucher to follow." As a result of the response, most -- but not all -- Facebook posts about the carrier were positive. In Knight Capital's case, a test program used with the software was included with the software. "The test program's job was to simulate buying and selling," said Hunsader. "It did its job too well." The beneficiaries, he said, were "traders who sensed somebody stupid out there. They took advantage of it. But retail investors couldn't sense this. They sold and got a lower price than they should have." The computers did not suffer one bit. -- Written by Ted Reed in Charlotte, N.C. >To contact the writer of this article, click here: Ted Reed >To follow the writer on Twitter, go to http://twitter.com/tedreednc.