Social media and mobile communication tools have come under increased scrutiny after web-savvy protesters took to Twitter, Facebook and BBM (BlackBerry Messenger) to organise demonstrations, riots, and even looting.

BBM, the private mobile phone messaging service, was targeted in particular because looters and rioters used it to organise acts of violence and theft in several UK cities.

In response, governments and civil-service authorities in the UK and US have begun to consider measures that would allow them to restrict access to internet and mobile networks, as well as services and applications in times of civil disturbance.

British Prime Minister David Cameron proposed measures that would allow the government to restrict users’ access to websites and services if they are being used to incite violence.

In San Francisco last week, BART (Bay Area Rapid Transit) authorities unilaterally shut down mobile phone reception in underground stations to hinder would-be protesters. Crowds had assembled in the stations protest a BART officer’s fatal shooting of a man authorities claimed was armed with a knife.

Australia is also considering measures that include ISP filtering, a minimum age for Facebook users, and mandatory parental access to kids’ online social network profiles to protect minors from online predators.

Supporters of such restrictions argue that abuse of communication tools like Twitter and BBM threatens public safety.

But opponents counter that restrictions on digital communications tools, including social networking sites and mobile networks, restrict civil liberties and are fundamentally undemocratic.

Today on The Stream, John Perry Barlow will join the show via Skype to discuss censorship. He is the co-founder of the Electronic Frontier Foundation and is an author and expert on cyberspace and digital rights. Also on the programme is Mike Butcher of the technology news website Tech Crunch. Butcher advises the mayor of London on technology issues.

These are some of the social media elements featured in this episode of The Stream.