SACRAMENTO, Calif. – People who strike back at ex-lovers and other adversaries by posting so-called revenge porn online face up to six months in jail and a $1,000 fine under a new law signed Tuesday by California Gov. Jerry Brown.

Senate Bill 255 defines the new misdemeanor crime as posting nude or sexually graphic images or video of an identifiable person online without their permission and “with the intent to cause serious emotional distress.”

According to State Sen. Anthony Cannella [R-Ceres], who authored the bill, revenge porn is a product of the Digital Age and has grown in significance along with online social networks. The practice is ruthlessly destructive, he noted in a prepared statement, because it is extremely difficult to expunge material from cyberspace. Adding to the trauma, he said, are laws that require victims to sue their virtual assailants in civil court — a time-consuming and expensive process.

“Until now, there was no tool for law enforcement to protect victims,” Cannella’s statement noted. “Too many have had their lives upended because of an action of another that they trusted.”

The law took effect immediately, but it may face First Amendment challenges. The American Civil Liberties Union has voiced opposition to the law on the grounds it is overly broad in restricting free speech.

Similar laws have met with limited success in other states. The Florida legislature this year declined to pass a revenge-porn bill, citing free-speech issues. Last year in Missouri, the state’s supreme court struck down part of a cyber-harassment law that used language similar to that in the California bill.