Before Jennifer Warns went to work for the plaintiffs law firm Bennett & Albright in August 2010, a partner at the firm made one thing clear. Warns would never be permitted to work on any case in which Allstate Insurance Company was on the other side. She was even instructed to restrict discussion of her 33-year career with Allstate to mundane and entirely personal topics.

What happened next begs two questions: How far will companies go to protect their secrets when employees leave? And how free are former employees to pursue jobs of their choosing?