I don't know about other states but in NH it is a state law that when you hire an employee you must put the wages and benefits that you offered the person in writing. Where is the trust there?
Most employers offer employee hand books that put in writing precisely what benefits the company will provide to the employee. You know, I have never had an employee put in writing what benefits our company will derive because of thier employment...Unless of course you consider the over their embellished resumes.
Trust goes both ways.