Census officials are trying to keep politics out of the world's biggest enumeration as for the first time they gather additional data on mobility, fertility, and other sensitive demographic indicators. The government has repeatedly proclaimed that the information will remain confidential and that the census won't be used as an excuse to send migrants back to their hometowns, but rising expectations of privacy have become a problem for the government in this year's enumeration. More than accuracy is at stake: The wrong numbers could have political ramifications if they raise questions about compliance with such policies as the one-child-per-family rule.