A California proposition that passed overwhelmingly in the fall would have forced registered sex offenders to hand over a huge amount of information about their online lives. Now, that proposition has been put on hold because of a preliminary injunction [PDF] from a San Francisco federal judge, who says that the new law is just too wide-ranging and could violate the constitutional rights of offenders.

The challenge to the law was filed the day after the election day by the Electronic Frontier Foundation and the ACLU on behalf of two of California's nearly 74,000 registered sex offenders. One was convicted in 1986 and the other in 1993, for unspecified offenses that aren't related to the Internet in any way. The ACLU has noted that some people are registered offenders for very old, misdemeanor offenses such as indecent exposure and don't warrant the kind of intense surveillance called for in Proposition 35.

The law would have required far-reaching surveillance of registered sex offenders. For instance, they would have had to disclose all of their online "identifiers," including e-mail addresses, usernames for any online services, and social media monikers. It would have made anonymous online speech for that population essentially impossible.

US District Judge Thelton Henderson had already granted a temporary restraining order blocking the law while he had more time to review the evidence. Today's injunction extends that, ensuring that these laws won't go into effect until the case is fully litigated, which could take months or years. It also suggests that Henderson is leaning towards striking down at least some of the law's provisions.

Proposition 35 also lengthens sentences for some types of sex crimes. Those provisions are not being challenged. Proponents of the law have called it a measure that cracks down on human trafficking.

"The court recognized that Prop 35's online speech regulations are overly broad and violate the First Amendment," said Linda Lye, staff attorney at the ACLU. "Stopping human trafficking is a worthy goal, but the portions of Prop 35 that limit online speech won't get us there. It's crucial that free speech remains free for all of us."

The proposition passed with 81 percent of the vote in November. Two key proponents of Proposition 35, Chris Kelly and Daphne Phung, have intervened in this lawsuit to defend their proposal and argued against the injunction in Henderson's court, to no avail. Kelly is the former privacy chief at Facebook and ran for Attorney General in 2010.