Short answer: preserve evidence before you do anything else, and do not confront them yet. The single most common way employers lose these cases is letting IT wipe and reissue the departing employee's laptop, which destroys the only record of what actually left with them. Read your own agreement critically before you assert it, and understand that a call from your customer to them may still be a breach.
The instinct is to call the employee, then call the customer. Both can wait a day. What cannot wait is the evidence, because the window in which it still exists is measured in days.
What should we preserve, and how fast?
Immediately, and before anyone is told they are under suspicion:
- The laptop and phone, unwiped. Image them. A reissued device is unrecoverable, and this is the step most often lost to ordinary IT hygiene rather than bad faith.
- Access, email, and file-transfer logs going back a year, not a week. In practice the copying starts long before the resignation.
- External device connections, cloud syncs, and mail forwarded to personal accounts. A thumb drive shows up in the logs by serial number.
- State business records. Check whether a competing entity was registered while they were still on your payroll. That single date reframes everything that came before it.
A 2025 Wisconsin case between an industrial parts and services company and a former technical sales employee, filed in Brown County Circuit Court
The employer did not discover the problem at the resignation. It learned only afterward — from a supplier — that its technical sales employee had been holding back leads to pursue through a company he had already registered, and it was roughly a month after his departure before it found he had approached one of its customers directly. What ultimately carried the injunction was not the customer contact but the forensic record: a commissioned examination of his company laptop established the thumb-drive connections, the files copied from the company's own SharePoint and Teams storage, and the deletions that followed. The court found a reasonable likelihood of success, irreparable harm, no adequate remedy at law, and granted relief.
Does it matter who called whom?
It matters, but far less than most employers and employees assume, because it depends entirely on your clause. Many Wisconsin customer non-solicitation provisions bar the former employee from soliciting, diverting, or accepting business from a protected customer. Where the word accept appears, an inbound call from your customer does not clear them.
Establish the sequence anyway. Who initiated, on what date, through what channel. It shapes the remedy you can realistically ask for and it is the first thing the other side will contest.
Should we send a cease-and-desist letter?
Usually yes, but not before someone has read your agreement against Wis. Stat. § 103.465. Wisconsin does not narrow an overbroad restraint to make it reasonable — it voids the clause entirely. So a letter asserting a covenant that will not survive scrutiny does more than fail: it signals that you have not analyzed your own document, and if it interferes with the employee's new work it can become the basis of a damages claim against you.
A letter that identifies the specific clauses you can actually enforce, aimed at the specific conduct you can actually prove, ends a meaningful share of these disputes without litigation.
How quickly do we have to move?
Injunctive relief requires showing irreparable harm and that money damages are inadequate. Delay undercuts both, and opposing counsel will argue that if the harm were truly urgent you would not have waited. That said, be realistic about the calendar: even a well-supported employer in the case above was several months from departure to interim relief, because the forensic work came first. Moving fast means starting the preservation and analysis immediately, not filing a thin motion in week one.
What should we claim?
Match the claim to the conduct. Breach of the specific covenant, breach of the duty of loyalty, trade secret misappropriation under § 134.90, unauthorized computer access under § 943.70 with the civil remedy in § 895.446, and tortious interference where a third party helped. Those fit, and they support the injunction that usually matters more than damages.
Federal racketeering and false-advertising theories are the ones to leave alone. Courts dismiss them routinely in departing-employee disputes because the conduct, however wrongful, is not what those statutes were written for — and an over-pleaded complaint invites the court to treat the whole filing as rhetoric.
An overbroad noncompete is void in Wisconsin — not narrowed. Find out where yours stands.
Talk to a Wisconsin Noncompete Attorney →