Contacting a Dating website?

The town I work for has a regulation prohibiting temporary signs in the ROW. Every Monday, I got out and pick up 30-40 signs from dating websites. I want to send them a letter telling them that what they are doing is illegal, and ask them to stop or get a permit, except, I can't get ahold of them in anyway! I go to the website, and all you can do is sign up to get all of the spam they can send at you. Does anyone have any advice or suggestions for me?