They knew who your girlfriend or boyfriend was. They knew where you parked your car. They stole your address book, they followed you to the zoo. They listened to you at meetings and wrote down which bottle shop you turned into.

“They” is ASIO, aka the Australian Security Intelligence Organisation, aka the secret police. And if you were politically active from 1949 to the 1980s — especially if you had any link whatsoever to the Communist Party — then the subject may well have been you.

Four well-known Australians met in Melbourne last night to discuss what they found in their ASIO files; each has written a chapter for the recently released book Dirty Secrets: Our ASIO files. What the authors found was a curious mix of amateurish, sloppy detective work and chilling intrusion and interference. The information is rather dated — ASIO files can be made public after 30 years (that’s gradually being reduced to 20 years). This is the Cold War-ASIO, a different beast to the present one.

The book’s editor Meredith Burgmann, an activist since the 1960s (and former Labor MP), said the research raised real concerns about how effective ASIO was. She said the authors had found their files were littered with mistakes, incorrect names and irrelevancies. It was “not very reassuring,” she told the Wheeler Centre audience last night. “They just pile fact on fact … but no analysis.”

Burgmann said one file was started on a boy aged four-and-a-half, who was suspected of subverting his teacher’s authority. But while some stories seem ludicrous and amusing, she pointed to a more sinister side; illegal activity by ASIO agents, and public service careers being ruined because of innocent contact with “communists and Trots”. Burgmann said when her own ASIO file arrived, wrapped in brown paper, she couldn’t bring herself to read it for some time.

Former High Court justice (and student politician) Michael Kirby lamented that his file was “disappointingly small”. It started when he was a boy of eight, because his grandmother married a Communist Party member. The man in question took Kirby to the zoo where the file showed “we were recorded near the lion’s den”, Kirby told the audience gravely.

But jokes aside, he said the book showed ASIO’s surveillance of people “went far beyond what was proportional”. Yes, Australia needs a security agency, but there should be strong checks on surveillance, Kirby argued. And he said Edward Snowden’s revelations about the use security agencies made of IT to watch people compounded the issue. “This is the new challenge of security in today’s world,” Kirby said. “We must keep sceptical about security agencies.”

Author, journalist and former anti-Vietnam war activist Anne Summers also spoke, detailing how her file showed that on the two occasions she tried to join the public service, ASIO got involved. She described the unsigned, handwritten notes on her file, decreeing her fate (on both occasions she did get a job). And Aboriginal activist Gary Foley ran through what he learned about the so-called “Black Power death list”, invented by authorities and leaked to the media but with no basis in fact. Foley paid his respects to “the resident ASIO person, wherever you are” — to uneasy laughter from the audience.

After the speech, Crikey talked to David McKnight, associate professor at UNSW and ASIO expert (and former Communist Party member). He explained that for the time in question ASIO was focussed on the Communist Party — members, people who worked there or had contacts there. The ASIO net extended to trade unions, left-wing groups, feminists, film societies … “progressive Left liberals often ended up with a file”. ASIO was particularly interested in anything that may have indicated someone had been recruited to spy for the Soviet Union. It was an “infinite task”, McKnight said.

McKnight explained an ASIO file was not a considered assessment, but rather a repository for bits and pieces. And he pointed out that while the ASIO of 1949 to the 1970s was keeping tabs on people considered subversive, the focus is now on counter-terrorism, counter-espionage, and political groups considered prone to violence.

So how do you access an ASIO file — your own or someone else’s? First, look to see if it has been made public via the National Archives of Australia’s RecordSearch. If a file has been made public it may not be digitised, in which case, request a copy via the webpage.

If there’s no file available you can request it be made public (there’s a factsheet here). You can do this for anyone, regardless of whether they’re a relation. Here’s the form to fill out. This is all done through the Archives, not ASIO (ASIO is exempt from Freedom of Information laws).

ASIO then decides whether to release the file, if there is one. McKnight said they mostly did release files although some information may be redacted. You can appeal a decision not to release a file or to redact information. And if you believe information on you is incorrect, you can apply to have a note added to your file. So yes, you can write your own ASIO file …