I fully understand that people feel their privacy has been violated when they see their information published on an unfamiliar site. Based on my own experience and previous outrage, all you can do is take the necessary steps to have it removed as simply complaining will not resolve anything. It takes time away that you would rather spend on anything else, but this is the price you pay for having access to all the information you wish to have at your fingertips with the Internet.
Voter records are public information and can be published with or without your consent. However, it should be removed from public view at your request. For Findthedata.org, submit a request through http://support.graphiq.com/hc/en-us/requests/new. Other sites, like COVoters.info used to require written mail to the website's owner, which was a huge hassle. The site now uses an online request that "might" work. Fortunately, it did for me. I hope Findthedata.org removes my information quickly as I already received an email confirmation.
Good luck to all.