I'm considering putting out sings like this in the spring. And while I do agree that they can ruin your reputation, I don't think it would be effected if you do as the original poster suggested and just put on the sign:for thought, i would never call anything posted like this, see the all the time and think what cheap crap and trashing up the place. think of that as well while spending money to advertise, it could damage your reputation.
With no business name. The only way people will make the association with you is if they took down the number and if that's the case they probably weren't offended.