I’m amazed at how many times an ex-employee acknowledges that they have executed a restrictive covenant agreement (a non-compete or non-solicitation agreement), then utters that it’s meaningless due to unenforceability.  This Alfred E. Neuman / “What, Me Worry” approach often leads to problems for both the sophomoric ex-employee, as well as the former employer.
The enforceability of restrictive covenants is governed by applicable state law, which will customarily be the state in which the employee worked or the state whose law was contractually agreed to govern.  Other than the few jurisdictions (such as California) in which specified restrictive covenants are unenforceable as a matter of public policy, as a general rule restrictive covenants are enforceable to the extent that they are reasonable necessary to protect a legitimate business interest.  This determination is fact specific and, again, determined under the particular governing state law.  All facts are different; all state laws vary – meaning that each case has to be evaluated on its own.