Just out of curiosity... has anyone ever heard of a daycare with a non-compete clause in its employment contract?

I was just talking to a friend of mine who's cousin just quit working at a daycare center. She quit because her contract was up and she refused to sign a new contract that had a clause in it stating that for the next four years, if she left that job, she would not be able to work within the city in any childcare position or even open her own home daycare.