Street vendors ply their trade from stalls in the ''tianguis'' as well as at non-officially controlled concentrations around metro stations and hospitals; at ''plazas comerciales'', where vendors of a certain "theme" (e.g. stationery) are housed; originally these were organized to accommodate vendors formerly selling on the street; or simply from improvised stalls on a city sidewalk. In addition, food and goods are sold from people walking with baskets, pushing carts, from bicycles or the backs of trucks, or simply from a tarp or cloth laid on the ground. In the center of the city informal street vendors are increasingly targeted by laws and prosecution. The weekly San Felipe de Jesús Tianguis is reported to be the largest in Latin America.