This is the VOA Special English Technology Report.

Today we take another look at facial recognition systems. These can friends in Facebook photos or help police identify suspects in the recent in Britain.

Kurt Roemer is chief security strategist for Citrix Systems in Fort Lauderdale, Florida. He says technology makes it easier than for governments to identify people.

KURT ROEMER: "Governments can go through and identify, profile and target people, basically in any order. And it is very much a line between effective law enforcement and privacy.”

Kristene Unsworth researches information policy at Drexel College in Philadelphia, Pennsylvania. She says she is concerned that governments and police are increasingly using facial recognition software without clearly defined .

KRISTENE UNSWORTH: “There is so much around this information that we don't really know how these kind of images or other sorts of personal data points are being used, how long the information is being . All of those kinds of things. So I guess for me it is an issue of transparency and .”

Questions like these are part of a larger debate about privacy and free speech. After the , British Prime Minister David Cameron raised the possibility of interfering with social networks. He said the question was whether it would be right to stop people from communicating "when we know they are violence, disorder and criminality."

China's official news agency Xinhua says the British government has "recognized that a balance needs to be between freedom and the monitoring of social media tools." Xinhua added, "We may wonder why western leaders, on the one hand, tend to indiscriminately other nations of monitoring, but on the other take for granted their steps to monitor and control the Internet."

Europe has some of the world's strongest policies on privacy rights. But Kurt Roemer says, like other western governments, they have not clearly defined their on new technologies.

KURT ROEMER: “China calling that out really shows that we have some issues to here from a policy perspective, in addition to technology.” :08

One debate involves an action in San Francisco on August eleventh by the Bay Area Rapid Transit system. BART disabled service in some of its underground stations for three hours. It says protesters were planning to use mobile devices to organize activities to train service. BART has faced protests over what activists say is police abuse by transit officers.

BART says it acted to protect public safety. The American Civil Liberties Union of Northern California says the decision was in effect an by a government agency "to silence its critics." The Federal Communications Commission says it is information about BART's actions.

And that's the VOA Special English Technology Report, written by June Simms. You can find part one of our report on facial recognition systems at voaspecialenglish.com. I'm Steve Ember.