Arguably they are, under the Uniform trade Secrets Act (which is CA law):
"... (b) Misappropriation" means: ... (2) Disclosure or use of a trade secret of another without express or implied consent by a person who: ... (C) Before a material change of his or her position, knew or had reason to know that it was a trade secret and that knowledge of it had been acquired by accident or mistake.
Interesting & upmodded. I didn't know that knowledge acquired by accident was protected from disclosure by those to whom the info has been revealed. Consider me educated.
"... (b) Misappropriation" means: ... (2) Disclosure or use of a trade secret of another without express or implied consent by a person who: ... (C) Before a material change of his or her position, knew or had reason to know that it was a trade secret and that knowledge of it had been acquired by accident or mistake.
In detail - http://news.ycombinator.com/item?id=1286907