The ACLU of Northern California (ACLU-NC) and EFF filed a federal class-action lawsuit to block implementation of unconstitutional provisions of Proposition 35 – a ballot measure passed by California voters that restricts the legal and constitutionally protected speech of all registered sex offenders in California.

Proposition 35 requires anyone who is a registered sex offender – even people with decades-old, low-level offenses like misdemeanor indecent exposure and people whose offenses were not related to the Internet – to turn over a list of all their Internet identifiers and service providers to law enforcement. While the law is written very unclearly, this likely includes email addresses, usernames and other identifiers used for online political discussion groups, book and restaurant review sites, forums about medical conditions, and newspaper or blog comments.

Even before the vote, California's sex offender statue was already very broad, with a lifetime registration requirement for even low-level convictions like nude erotic dancing on stage at a bar. The state has the tools to determine who presents a risk to public safety and who doesn't – but this statute applies to everybody, no matter what the risk.

In January 2013 the court issued a preliminary injunction, blocking enforcement of Prop. 35. The Ninth Circuit Court of Appeals affirmed that order in a November 2014 opinion. In early 2015, the state of California announced it would not try to appeal the Ninth Circuit's ruling to the Supreme Court.