Maroussi Municipality in northern Athens said yesterday that it had begun pulling down about 100 illegal billboards in its district in an ambitious bid to tackle a booming illegal industry. Maroussi Mayor Giorgos Patoulis told Skai Radio and Television the cleanup operation will take place over the next 45 days. Experts say there are an estimated 15,000 illegal advertising signs around Athens, representing an industry valued at around 200 million euros per year. Advertising companies have often been accused of using heavy-handed tactics to keep their advertisements in place. The relatives of road accident victims have petitioned for the removal of roadside billboards, saying they pose a threat to drivers. Passengers in car accidents are often rammed against the large metal structures.