Teradyne v. Clear Communications: Trade Secrets

An Illinois federal court held that alleging ex-employees know your secrets and joined a rival does not state a threatened-misappropriation claim.

Teradyne, Inc. v. Clear Communications Corp., 707 F. Supp. 353 (N.D. Ill. 1989), decided February 9, 1989 by Judge James B. Zagel of the United States District Court for the Northern District of Illinois, is the decision that gave the inevitable disclosure doctrine its language while sharply confining its reach. Years before the Seventh Circuit made the theory famous in PepsiCo, Inc. v. Redmond, 54 F.3d 1262 (7th Cir. 1995), Judge Zagel confronted an employer that wanted to enjoin a rival simply because former engineers who knew its secrets had gone to work there. He dismissed the complaint, with leave to replead, holding that knowledge plus employment is not a threat. To state a claim for threatened misappropriation, a plaintiff must allege facts showing a high probability that disclosure is inevitable and imminent.

At a glance

Case: Teradyne, Inc. v. Clear Communications Corp., 707 F. Supp. 353 (N.D. Ill. 1989)
Court: U.S. District Court for the Northern District of Illinois
Decided: February 9, 1989, by Judge James B. Zagel; complaint dismissed, with twenty-one days to replead
Holding: An allegation that former employees know the plaintiff’s trade secrets and have joined a competitor in the same field does not, without more, state a claim for threatened misappropriation under Illinois law.
Significance: Supplied the “inevitability” vocabulary later adopted by PepsiCo v. Redmond while demonstrating how narrow threatened-misappropriation claims are meant to be at the pleading stage.

The doctrinal frame: threatened misappropriation

Illinois, like most states that adopted the Uniform Trade Secrets Act, permits injunctions against not only actual misappropriation but also threatened misappropriation. The statutory hook is real: a court may enjoin conduct that threatens to disclose or use a trade secret before any secret has actually leaked. The hard question is what counts as a threat. If merely knowing a secret and taking a competing job qualified, then every employee who moved within an industry would be enjoinable, and trade-secret law would swallow the freedom of workers to change jobs and use their general skills.

Teradyne is the decision that drew the line. Judge Zagel accepted that Illinois recognizes threatened misappropriation and that inevitable disclosure can, in principle, constitute such a threat. His concern was pleading rigor: an inevitable-disclosure theory has to rest on alleged facts that make disclosure genuinely probable and imminent, not on the bare coincidence of knowledge and competition.

The facts and the pleading defect

Teradyne’s telecommunications division in Deerfield, Illinois designed and made automatic test equipment for telephone systems, selling to public networks owned by telephone companies and common carriers. Three long-time employees left, and one of them formed Clear to test telephone systems for private networks, a market Teradyne was preparing to enter but did not yet serve. Teradyne’s complaint asserted that there was a high degree of probability of inevitable and immediate disclosure and use of its trade secrets by the departed employees in Clear’s competing business. That, Teradyne argued, was a threat the court should enjoin.

Judge Zagel found the pleading insufficient. The complaint, he explained, did not allege that the defendants had in fact threatened to use Teradyne’s secrets or that they would inevitably do so. It alleged only that the employees knew the secrets and had joined a competitor. That, the court held, was a legal conclusion dressed as a factual allegation. The phrase “inevitable disclosure” cannot substitute for facts showing why disclosure is inevitable. Because the complaint offered no such facts, it failed to state a claim. The court dismissed the complaint and gave Teradyne twenty-one days to replead in line with the opinion, so the dismissal closed the pleading as filed rather than the case.

The court’s reasoning: what a real threat looks like

The lasting value of Teradyne lies in the court’s description of what would have sufficed. Judge Zagel indicated the claim would have cleared the pleading bar had Teradyne alleged one of several things: that Clear intended to use Teradyne’s trade secrets, that the former Teradyne employees had disavowed the confidentiality agreements they signed, or that Clear could not operate its competing business without using Teradyne’s secrets. Each of those allegations supplies the missing link. Each converts the abstract worry that a knowledgeable employee might someday slip into a concrete, fact-based probability that use is coming.

Underlying that analysis is a policy the court made explicit in substance. If the law enjoined every employee who carried valuable knowledge into a competing role, it would impose a judicially created non-compete on workers who never agreed to one and would freeze labor mobility across entire industries. The inevitable disclosure doctrine, to be legitimate, must be reserved for situations where the risk of misuse is demonstrably high, not merely conceivable. Teradyne thus married a recognition of the doctrine to a demand for particularity that keeps it from devouring the rule that employees may use their general knowledge and skill.

From Teradyne to PepsiCo

Six years later the Seventh Circuit decided PepsiCo, Inc. v. Redmond, the case usually credited with establishing inevitable disclosure in the modern era. PepsiCo did not repudiate Teradyne; it applied Teradyne’s framework to stronger facts. There, a senior executive with detailed knowledge of PepsiCo’s strategic plans left for a direct competitor in the sports-drink market, and the record showed he could not perform his new job without relying on PepsiCo’s confidential plans, along with evidence of a lack of candor about his move. Those facts supplied precisely the concrete probability that Teradyne said was required. Read together, the two decisions form a single doctrine: inevitable disclosure is available, but only when the plaintiff can show, with facts, that the departing employee will inevitably draw on specific secrets in the new role.

Open questions

Teradyne was decided on the pleadings, which limits how much it settled. It tells litigants what allegations fail but leaves the sufficiency of borderline complaints to case-by-case judgment. How specific must a plaintiff be about which secrets are threatened, and at what point does an allegation that a competitor “could not operate without” the secrets cross from conclusion to fact? The decision also predates the federal Defend Trade Secrets Act of 2016, whose injunction provision, 18 U.S.C. § 1836(b)(3), forbids conditions that prevent employment based merely on what a person knows and requires evidence of threatened misappropriation rather than information the person knows. How Teradyne’s pleading standard interacts with that federal limit, and whether the DTSA further narrows the theory, remains a live question in the many jurisdictions still sorting out inevitable disclosure.

Implications for employers and employees

For employers: Do not file a threatened-misappropriation claim on knowledge alone. Plead specific facts, evidence of intended use, disavowed confidentiality obligations, or a role that cannot be performed without your secrets, or expect a Teradyne dismissal.
For departing employees: Moving to a competitor in the same field is not, by itself, actionable. The employer must show a concrete probability that you will use its secrets, and general industry knowledge you are entitled to keep does not count.
For litigators: Front-load particularity. Identify the trade secrets, tie them to the specific tasks of the new job, and marshal facts about intent or the impossibility of performing the role cleanly.
For drafters: Because inevitable disclosure is hard to plead, a narrowly tailored, enforceable confidentiality or non-solicitation agreement often protects more reliably than hoping a court will infer a threat after the fact.

Frequently asked questions

What did Teradyne v. Clear Communications actually decide? The court dismissed the complaint and gave Teradyne twenty-one days to replead. It held that alleging former employees knew Teradyne’s trade secrets and went to work for a competitor in the same field, without more, did not state a claim. A plaintiff must allege facts showing a high probability of inevitable and imminent use.

How does Teradyne relate to PepsiCo v. Redmond? Teradyne came first, in 1989, and supplied the analytical vocabulary of inevitability. When the Seventh Circuit embraced inevitable disclosure in PepsiCo v. Redmond in 1995, it built on Teradyne’s framework but found the demanding facts present there that Teradyne found missing.

Can a plaintiff win on inevitable disclosure under Teradyne? Yes, but only on strong facts. The court indicated the claim would survive if the plaintiff alleged that the competitor intended to use the secrets, that the employees disavowed their confidentiality obligations, or that the competitor could not operate without the plaintiff’s secrets.