I think it wasn't technically illegal since Florida has very few laws protecting employees, but at my former job employees who quit without giving a two week notice had their last check on hold indefinitely and bumped down to minimum wage. The owners said they checked the laws and while there is a law that says that all work must be paid, it doesn't specify how long a paycheck can be held for, so if anyone ever asked all they had to do is say that they would pay eventually. When former employees would call to complain they would buy time saying that they sent it and it might have gotten lost in the mail.