A new report from Human Rights Watch details a hair-raising trend in China: many Chinese citizens who come to Beijing to protest unlawful conditions at home are being thrown into prisons, called China's "black jails." The report comes as President Obama prepares a two-day visit to Beijing during his tour of Asia. "The existence of black jails in the heart of Beijing makes a mockery of the Chinese government's rhetoric on improving human rights and respecting the rule of law," a Human Rights Watch director says. The lock-ups are part of an effort to discourage petitioners, according to the agency. Chinese officials denied the existence of such a program to The Independent newspaper.