"Be sustainable - Don't buy sex!" exhorts a postcard that is being distributed to guests of 160 hotels in Copenhagen during the UN Climate Summit. The proprietors of the lodging establishments received the postcards along with a letter from Lord Mayor Ritt Bjerregaard requesting they not facilitate transactions between the COP15 guests and the city's prostitutes. In response to their local representatives' attempt to thwart a potential bump in business, the Sex Workers Interest Group (SIO) has co-opted the postcards as a marketing tool by announcing that anyone who brings one to the group along with their COP15 ID badge will get to indulge in the sex workers' services for free!