Whether criminals are hacking our passwords, or Anonymous is simply making a statement, the disruptions and data breaches exact a heavy toll in terms of time, money, and security.How that digital revenge is wreaked, and whether any of it is legal, are issues being actively debated right now—to the extent that anyone wants to talk about it, let alone admit to trying it. Hacking back at a cyber-assailant is tempting, but it’s just as illegal as the original cyberattack.