What the agreement can restrict
Confidentiality agreements can restrict the use of genuinely confidential business information, but they generally cannot stop you from using the general skills and knowledge you built over a career. They also have legal limits. Agreements generally cannot prevent you from reporting possible legal violations to a government agency, and federal and New York law restrict how nondisclosure terms can be used to silence claims of harassment or discrimination. Whether an agreement is enforceable as written depends on its wording, the governing law, and what you actually did with the information. An accusation is the beginning of the analysis, not the conclusion.
Files, devices, and accounts
The most important early step is to take stock of what company material you still have, without deleting anything. Deleting files after a demand letter arrives can look like concealment and can create problems worse than the original claim. Do not forward company files to anyone, including a new employer, and do not keep opening them. Ask counsel how to return or quarantine the material properly, which may involve a neutral forensic process. Your personal messages and records of your own pay and performance are generally yours to keep, but company documents fall in a different category, and the line should be drawn with advice.
Responding to the demand
A demand letter often asks for a signed certification, the return of materials, and sometimes a promise about future work, all within a short deadline. Do not sign anything or respond on your own. In a first meeting, we review the agreement, any related non-compete or non-solicitation terms, the facts about what you took or used, and whether your new employer should be involved, since it may have its own exposure and its own counsel. Some of these disputes settle into an agreed process for returning information and clarifying restrictions, while others move quickly toward a request for an injunction, so preparation matters from the first day.