[chasing]

I imagine if you offer your opinion about the price in a professional context where your opinion can affect the actual value of the property then you might have to follow some rules.

If you drive by a house and say "this house doesn't look like it's worth shit" you're probably not going to wind up in court after someone complains that said house is worth quite a bit more than shit and you're driving the price down.

Laws actually can be vague while remaining Constitutional. Sometimes it's unavoidable. Court cases can be used to refine the edges.

[razwall]

Actually this has come up before with a similar law in Arizona, where the state tried to ban Zestimates. Volokh's analysis basically agreed with me (http://volokh.com/posts/1177792494.shtml). Though I couldn't find any info about what ultimately happened with that case.

[dtrizzle]

I'm pretty sure the Arizona legislature changed the law to make it clear that Zestimates were lawful. http://supreme.findlaw.com/legal-commentary/must-zillow-the-...

[tssva]

There was never an actual legal case. There were just cease and desist letters with threats of a case. Before any actual legal case could materialize the law in AZ was changed to allow automated appraisals without certification as long as no money changed hands for the appraisal.