Friday, the Assembly passed this bill (Assembly Bill 534), by a 72-0 vote:
Any person who [making the information available to another person through any medium] [any] informationdescribing or depicting a child, the physical appearance of a child [defined as age 14 or younger], the location of a child, or locations where children may be found with the intent that another person imminently use the information to commit a crime against a child and the information is likely to aid in the imminent commission of a crime against a child, is guilty of a misdemeanor, punishable by imprisonment in a county jail for not more than one year, a fine of not more than one thousand dollars ($1,000), or by both a fine and imprisonment. [Emphasis added.]
This is likely constitutional — but only because it's so narrow as to cover virtually nothing, except what is already almost always felony aiding and abetting. It certainly doesn't cover the menacing behavior of "pedophile blogger" Jack McClellan, whose behavior I suspect prompted the law.
The Supreme Court has recognized an exception to First Amendment protection for so-called "incitement" — "advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action." (That's the Brandenburg v. Ohio test.) The statutory language seems clearly borrowed from the incitement test, and the statute is therefore likely constitutional. It's true that it speaks of provision of information rather than advocacy of conduct, but I suspect courts will read the Brandenburg exception to equally cover pure information and advocacy, so long as both are intended to and likely to produce imminent lawless action. Information is at least as dangerous in such a situation as is advocacy (and may be more dangerous), and since it's no more constitutionally valuable in such a situation than is advocacy.
But while the narrowness of the proposal makes it constitutional, it also makes it largely pointless. "Imminent," in the Court's incitement jurisprudence, basically means "to happen within a few hours or at most a few days." The Court has expressly concluded (in Hess v. Indiana) that when the contemplated action is "at some indefinite future time," the imminence requirement isn't satisfied. So all that the law will cover are statements like, "Here's where you can find that girl whom you're planning to rape or abduct tonight," which would usually qualify as aiding and abetting of the crime — a felony or an attempted felony — in any event. (The one situation where the law might make a difference is if no felony is actually attempted by the recipient; since criminal liability for aiding someone is derivative of that someone's committing or attempting a crime, generally speaking an attempt to aid someone who does nothing with the aid isn't criminal aiding and abetting. But even there it may well be criminal solicitation, or in some situations evidence of a criminal conspiracy.)
On the other hand, the statements that McClellan was making, and that probably aren't already covered by the law (partly for First Amendment reasons) — "Here's a picture of this girl, isn't she hot, wouldn't it be great if it was OK for us adults to have sex with her" — wouldn't be covered by this statute, either: If they assist any action, it is action "at some indefinite future time," which under Hess doesn't qualify as "imminent" action.
Of course, California courts have the power to read the statute more broadly than the U.S. Supreme Court's incitement exception. But I doubt they will, given how clearly the statutory text is modeled on that preexisting legal rule. (It's a longstanding rule of statutory construction that statutes that appear to refer to existing legal doctrines will be interpreted as incorporating the existing definitions of those doctrines.) And if they do interpret it so broadly, that will likely make the law unconstitutional.
The statute also provides that, "Any parent or legal guardian of a child about whom information is published in violation of [the provision quoted above] may seek a preliminary injunction enjoining any further publication of that information." I think that's likely unconstitutional under Vance v. Universal Amusement Co., for reasons discussed here.
If you're really hungry for more — much more — on the problem of crime-facilitating speech, you might take a look at my Stanford article on the subject.