Writing letters to politicians, local authorities and the like can often seem like a waste of time, but it isn't. One person writing won't achieve everything all at once, but lots of people writing over a period of time will make a difference. Please choose your time, and make the effort. The tone of the letter is important. Politeness is much more likely to gain results than rudeness.
Insults are nearly always highly counter productive.
Of course that does not stop you from making the strength of your feelings abundantly clear. It's disgraceful that they don't all have one. However, paper can carry more weight than email so think about which medium to use. The media There are a large number of different newspaper, radio and TV providers and several regulators. Naturists should complain to both media and regulators about inappropriate treatment of nudity.