Facebook's Graph Search tool, now widely available to users in the U.S., could frighten people concerned about their online privacy, according to analysts and consultants. The tool will allow for more in-depth searching of friends old and new, photos and other interests. "It is every stalker's fantasy tool," said Max Wolff of Greencrest Capital. "It could actually alienate people. People are extra-sensitive about privacy because of the [National Security Agency] scandal. So the average user could jack up their privacy settings and decide to disclose less on Facebook, which could hurt advertising."