The Valparaíso trolleybus system has become one of the icons of the city, considered an important part of its cultural heritage.[3][17][18][19] Many porteños – as residents of this port city commonly call themselves – are fond of their city's distinctive and historic trolleybus service and have spoken up in its defense when the system has come under threat of closure.[5][18] The private operating company receives no government subsidy, and at times it has struggled financially, putting the system in danger of being closed. One such occasion, the company's announcement in May 2007 of imminent closure plans, brought an outcry from local citizens, and even Chile's president, Michelle Bachelet, expressed support for keeping the trolleybuses going.[6][19]