Which would be appropriate, except the guys in the story didn't "take from others". They analyzed the system, found a flaw, and told the city about it. Moreover, they are not telling other people how to hack SF's specific system, nor does the story imply that they are continuing to make or use the "free" cards. If it turns out that other people are already secretly using this technique, the researchers may have saved SF and other cities a lot of money.