Failure to protect against misappropriation is an affirmative defense in CA.
Dorsey had duty to keep Twitter's TSs. "It is misappropriation to disclose or use another’s trade secret, knowing or having reason to know, that...the trade secret was acquired under circumstances giving rise to a duty to maintain its secrecy or limit its use, or was derived from or through a person who owed a duty to maintain its secrecy or limit its use. (Cal. Civ. Code, §§ 3426.1(b)(2)(B)(ii) and (iii).)"