Whose conduct is on the line
The person who took or used the information is the obvious target, but exposure often extends further. A business that receives confidential material can face claims if it knew or had reason to know the information arrived through improper means or in breach of a duty of confidence. Managers who directed or encouraged the use may be named personally. Federal law, through the Defend Trade Secrets Act, gives owners a claim in federal court, and state law runs alongside it. New York has not adopted the uniform trade secrets statute that most states use, so claims under New York law rest largely on court decisions, which is one reason the analysis there can differ from a neighboring state.
How exposure is measured
Courts usually look first at whether to stop ongoing use, through an injunction, and then at money. Monetary relief is commonly framed around the owner's loss or the other side's gain, and some courts use a reasonable royalty when neither can be measured well. Where the conduct is found willful and malicious, federal law allows additional damages and, in some circumstances, attorney's fees. Fee shifting can also run the other way when a claim is brought in bad faith. Which measures are realistic in a given matter depends heavily on the evidence of use, not just of taking, and on the forum.
Sorting out your own position
If you are the owner, we start with what the secret actually is, how it was protected, and what proof shows it was used rather than merely copied. If you are an accused individual or a hiring company, the early questions are what came in the door, who touched it, and whether it has been quarantined in a way that can be documented. Do not delete or return material on your own, because how it is handled can become part of the case. Bring the relevant employment and confidentiality agreements, any correspondence about the departure, and a list of people involved. A first meeting usually decides whether an early resolution, such as a forensic return protocol, is worth proposing before positions harden.