Protesters stand in the door of a Bay Area Rapid...

Protesters stand in the door of a Bay Area Rapid Transit train at the Civic Center station in San Francisco on Aug. 15. Rather than resort to another shutdown of subway cellular service to deter protesters, the San Francisco Bay Area's transit agency closed down stations in the path of marchers, inconveniencing thousands of evening commuters. (2011) Credit: AP

Social media, once credited with the blossoming of the Arab Spring, is shriveling in the British Winter. Eight months ago, access to the Internet and the communications tools empowered by it -- Facebook, Twitter and BlackBerrys -- were heralded by the West as a new human right. After hooligans looted London for days, the British government denounced those very same tools as dangerous weapons that must be controlled.

The reality is they are neither. Technology is agnostic, whether it inspires millions to demand democracy or instructs hundreds to riot. The core dilemma is a classical one: When can a government censor the free speech and right to assembly of its citizens? And does new technology alter the rules of the game?

This is a challenge whose immediacy should be apparent to our political and legal systems. We need to engage in a national and a local debate about when government should act and what behavior we, as a society, will allow.

Failure to do so means risking the overreach now happening in Britain, as elected officials and the judiciary react to the explosive and frightening civil unrest that recently took place there. After Prime Minister David Cameron said, the "free flow of information can be used for ill," the censorious government of China -- which routinely restricts search engines, interferes with Twitter and shuts down Facebook pages -- pretty much said, "Told you so." A recent editorial in Xinhua, the state media, accused the West of "laying undue emphasis on Internet freedom," saying, "the British government eventually recognized that a balance needs to be struck between freedom and the monitoring of social media tools."

Most of those who took to London's streets were thugs who deserve to be punished for their actions. But what about Jordan Blackshaw, 20, and Perry Sutcliffe-Keenan, 22, who in separate incidents, in the midst of the violence, used Facebook to get a virtual piece of the action? Blackshaw created an event called "Smash Down Northwich Town" and set up a meeting the next afternoon behind a local McDonald's "to get this kickin' off all over." No one showed up -- except for the police who arrested him. Sutcliffe-Keenan sent an invitation to take part in "Warrington Riots" and posted a photograph of a clash with police. He called it a joke. The Guardian newspaper said both "failed to rouse any kind of rabble."

In the United States, words that don't incite violence or mayhem usually are considered speech protected by the First Amendment, no matter how stupid the message. In Britain, however, a judge agreed with police that the men used social media "to promote and incite behaviour that would strike fear into the hearts of our communities." Both are now serving four-year prison terms, not for their actions, but for their messages. They may find some solace in the "Free Jordan Blackshaw & Perry Sutcliffe-Keenan" Facebook page.

While the use of Twitter and BlackBerrys by London rioters made headlines, the most controversial issues since deposed Egyptian president Hosni Mubarack shut down the wireless service in Tahrir Square happened in San Francisco on Aug. 11. The Bay Area Rapid Transit police, fearing a protest over their killing of an apparently mentally ill homeless man more than a month earlier, cut the power to the system's wireless cell towers for three hours. The police said they believed public safety would be jeopardized if a downtown station became overcrowded.

That protest never materialized, but demonstrations about the wireless shutdown did close stations. The hacker group Anonymous is now wrongfully slicing and dicing every BART database in revenge, including making public personal data about its police.

While the action by the BART police seems precipitous, the fast-paced threat of criminal activity enabled by social media is indeed a serious problem. In Philadelphia, the mayor has ordered curfews for teenagers in response to a rash of flash-mob robberies, where smartphones were used to organize an overwhelming rush on convenience stores. Cleveland's city council passed an ordinance making it illegal to use social media to set loose a flash mob, but the mayor vetoed it, saying there had to be a better way to control this behavior "than throwing away the Constitution."

He's right. In this summer of discontent, just how we deal with it is the question that needs to be answered.