Two South African lobby groups this week picketed a biotechnology conference in Johannesburg over the controversial issue of genetically modified (GM) food. A small group of protesters from the Environmental Justice Networking Forum and the South African Freeze Alliance on Genetic Engineering held up placards with slogans like "Say Yes to Organic Agriculture" and "Warning: GM foods can damage your health". Sister Angelica Loub, one of the protesters, said she had environmental, social and economic concerns about genetically modified foods.