Mustang Forums
I wouldn't listen to 90% of what they say around there. (not to discredit the people who actually might know what there talking about.)
A properly cleaned quality MF should not do any damage to the paint at all. As long as it is used properly (right amount of pressure) and in the right situations (removing wax, drying off the car....) I say it is some of the safest drying/multipurpose towels that can be used on cars period.