Some New Jersey state troopers got law degrees with the help of a state-sponsored loan repayment program. Then sought to practice law on the side — doing wills, real estate closings, etc. Then the State Ethics Commission for the Department of Law and Public Safety decided that it was unethical for troopers to engage in the private practice of law. The troopers sued, alleging (among other things) that the prohibition violated their rights under the 14th Amendment. Alas, their case did not get far, as the U.S. Court of Appeals upheld the restriction, finding that the state had a rational basis for concluding the rule would prevent some potential conflicts of interest.
(Hat tip: John Steele)