Mayor Michael Bloomberg says putting fingerprints on social security cards would help control the nation's borders, and give employers a way to check whether potential hires are legal citizens..."This is a plan that's ill advised and should not be pursued and is incompatible with some of the values that the mayor claims to be important to him," said Donna Lieberman of the New York Civil Liberties Union. Things like preventing the marginalization of the immigrant community. "When we add a layer of documentation in order for people to do basic activities there are people that are vulnerable ... for whom this just means they are pushed to the outskirts," Lieberman said.