Playwrights are probably a nightmare to live with. I’m not sure. I live alone now. Probably because I’m a playwright and I was a nightmare to live with. It might be due to the fact that when working on a new show you become so immersed in it that you see its relevance and equivalence all around you – in every news story or passing event. “Oh, that’s a bit like the play I’m working on,” you mutter, as the person you’re talking to sighs and tries to make eye contact with someone else.

Recently I’ve been seeing anarchy everywhere. In this case, however, I don’t think it’s just because I’m opening a show about political radicalism in the 70s. I think it’s because it’s in the air…

“Get pissed, destroy” scream the Sex Pistols in the closing notes of Anarchy in the UK, their first single release. The young London revolutionaries hanging out in the bookshops of Camden and the communes of Notting Hill might not have recognised themselves in that sentiment. Their movement was not about mindless rioting; theirs was an intellectual one, born out of universities and coffee houses. Their obsessions were social justice, freedom, and the rejection of a class-based, unrepresentative establishment in power.

By this definition, the Scottish independence referendum was a big fat piece of modern anarchy, surely. Its purpose was nothing short of the overthrow of a government no longer believed to represent its interests, in the quest (in the eyes of its supporters) for better representation and distribution of wealth, a more interdependent way to live.

What excited me about the independence debate (conflicted as I am about its aims) is the same thing that excites me about the activism of the 1960s and ’70s (conflicted as I am by its methods). There is/was a genuine belief in the possibility of change; a genuine belief that your participation means something and matters; that there is a choice about the direction of travel, and nothing can be taken for granted – not even the kingdom itself.

Possibly the grassroots mobilisation of people on to the streets of Scotland, or the arrival of online pressure groups like 38 Degrees, the cult of Occupy on the left or, dare I say it, even the arrival of self-defined “anti-establishment” (they’re not) Ukip on the right… maybe all of this means the anarchic spirit, assumed to be a political anachronism, is alive and well in the UK. It’s just dressed in nicer suits, and armed with iPads instead of bombs.

Where once activists thwarted big business by marching on their premises, online collectives like LulzSec, as featured in Tim Price’s new play, Teh Internet is Serious Business (if that misspelling isn’t anarchy then I don’t know what is), can paralyse corporations with a denial-of-service attack from their bedrooms.

In The Angry Brigade, a play I’ve written for the Theatre Royal, Plymouth and Paines Plough (a company that promotes new playwrights, born 40 years ago in the heat of the counterculture movement), they did things differently.

You might not have heard of the Angry Brigade. I couldn’t believe I hadn’t heard of them when I eventually heard of them. During their campaign, between 1970-71, they sent communiqués to newspapers and the authorities, made using a children’s printing set.

“We are no mercenaries. We attack property not people,” they wrote in communiqué 5. And in communiqué 7: “The politicians, the leaders, the rich, the big bosses, are in command… THEY control. WE, THE PEOPLE, SUFFER…” And in Communiqué 9, they wrote: “The AB is the man or woman sitting next to you. They have guns in their pockets and anger in their minds. We are getting closer.”

A lot is still contested and unknown. Some define them as the first home-grown mainland terror cell – perhaps surprising, today, given they were white, university-educated men and women in their 20s. An urban guerrilla outfit who set off – or were linked to a network that set off – 25 explosions around London, at the homes of cabinet ministers, senior judges, police commissioners. They detonated devices in fashion boutiques and monuments to capitalism, such as the Post Office tower. When they were eventually caught – living together in a Stoke Newington flat, in what the tabloids described as a “bomb factory” – alleged perpetrators John Barker, Anna Mendelssohn, Hilary Creek and Jim Greenfield were sentenced to 10 years, following the longest criminal trial in English history. So long, in fact, that in a classic example of the idiosyncrasy of the very British establishment under attack, the judge brought in a cake for one of the defendants on their birthday.

And yet, silence has defined them since their release. Anna Mendelssohn became Grace Lake. Her family and friends tell me of her relocation to Cambridge, as a mature student exploring her gifts as a poet and painter. I don’t know the whereabouts of Jim Greenfield, the son of a Widnes lorry driver. Hilary Creek is thought to be in France, possibly Italy. John Barker, a novelist, spoke eloquently of his undiminished fury to the Guardian earlier in the year. “Looking back, the kind of things the Angry Brigade did would be far more relevant now,” he said. “But I feel angrier than I ever felt then. The way in which the crisis of 2007 got flipped, so that suddenly it’s not bankers but people living on welfare who are the problem, was extraordinary. These are horrible times.”

It’s that financial crisis that surely led to the activism, such as it is, we observe around us today. It pulled open the wizard’s curtain, caused a glitch in the matrix that made us blink. Prior to that, in a world post-Thatcher and “Third Way” Blair, there was one assumed way to organise the world. This is being questioned again. And if we are to believe in the politicisation of normal men and women, young and old, around the dinner tables and bar stools of Scotland, then something has happened. Something has changed.

“Blow it up or burn it down” was the cry of the Angry Brigade. I’m not advocating that. But as a politically engaged young person it was always disconcerting to be continually told how young people were not politically engaged. Our tools are different – and I’m not always convinced by their effectiveness. Where once there were trade unions there are now Facebook groups. Where once we marched, now we sign petitions. But if anarchy is defined (as it was intended) as the belief in progress and change when progress and change become necessary, then through the mere asking of the question “Why does it have to be this way – just because it always was?” perhaps the reigniting of a little anarchy in all of us is a healthy, exciting and, above all, quite a surprising thing.

The Angry Brigade by James Graham is at Theatre Royal, Plymouth, before touring to Oxford, Warwick and Watford. Click here for details