According to a SHRM survey on office romance, at least 42% of employers have regulations in place addressing office romance

According to a SHRM survey on office romance, at least 42% of employers have regulations in place addressing office romance. Do some research on a variety of companies about office romance policies. Also, does is it a surprise that only 42% of companies have policies- what about the other 58%?
Can employers forbid romantic relationships at work? What concerns might other employees have? (For example, Barbie and Ken making out in the lunchroom.) Should legal be involved?
What points would you as a manager consider when developing a dating policy in your company?