Amid growing flak that its new advertising system reduces users' privacy, Facebook made some changes this week. Now users can "opt in" to having their online shopping broadcast to friends; before they had to "opt out" - a problem if they didn't know their purchasing decisions were being broadcast and they were, for example, buying holiday gifts and wanted their friends to be surprised). "The move comes a week after MoveOn.org, the non-profit public policy advocacy group, joined a growing chorus of critics of the new service," the Financial Times reports. Facebook did stop short of allowing users to opt out of the system altogether, the FT added. The system is "part of an effort to boost revenue growth by tapping into the deep social connections between Facebook users" - aimed at making social networking attractive to advertisers by tapping into the viral-marketing idea that friends are influenced by what their peers buy. Among other concerns was that of a University of Minnesota law professor. Citing his view, a New York Times blog asked the question, "Are Facebook's Social Ads Illegal [in New York]?" And consumer privacy advocates are pushing for greater control for consumers of their personal data on the Internet (see this at the Center for Democracy and Technology).