So an employer who claims they are protecting their valuable secret client sources is going to have to show that the information was not available to everyone else in the industry.
Existing customer lists or unique sources may well be protected, but chamber of commerce directories are probably not. Public health or safety would not be served: This primarily applies to doctors, nurses, and people in specialized scientific and health areas.
If there is a shortage of people in a particular specialty, or in a particular geographic area, then the employer probably cannot enforce a non-compete even if all the other requirements are met.
If you are one of 10 brain surgeons in the country who can perform a particular procedure, your employer probably can’t prevent you from saving people’s lives.
That doesn’t mean you can’t get out of yours if you’re willing to fight.
What usually happens is the employer sends a letter to the employee and the new employer, threatens to sue both, and the employee gets fired from their new job, even where they told the new employer about the non-compete.
Phone books, professional directories, the internet, notification services, are all sources that are available to anyone in the industry.
In general, I tell people to assume their non-compete agreements are enforceable, and not to sign them unless they can live with the restrictions.