Legal Recources Against Above-Board Spamming?

brandyn asks: "Marketshare Recovery is apparently selling my e-mail address to companies and telling them I am an "opt-in" customer, as if somehow opting in for notifications from one company is a blank check written to every spammer in the world. More, the company who spammed me claims M.R. told them I opted-in while making an online purchase within the last six months. In truth, I never "opt-in" for e-mail, and the only online purchase I've made in the last couple of years used a different address entirely. So in the case of my address, they're almost certainly fraudulently representing it to the companies who are purchasing it from them, ultimately at my expense. What can I do to recover that expense from them and/or prevent them from continuing to cost others?"