WASHINGTON (AP) — The U.S. charged seven hackers linked to the Iranian government with executing large-scale cyberattacks on dozens of banks as well as a small dam outside New York City — intrusions that law enforcement officials said reached into America's infrastructure and disrupted the nation's financial system.An indictment announced Thursday by the Justice Department shows a determination by overseas hackers to cripple vital American interests, the officials said.The hackers are accused of infecting thousands of people's computers with malware to create a network used to overwhelm servers of major institutions to knock them offline.