They used off-the-shelf software to intercept all the data to and from the internet via a laptop plugged into the office's internet router. Using free online tools they stripped out about 99 per cent of what was captured, including the content of communications, and the industry-standard definition of web history – http and https traffic, which is all the data sent between your computer and the web server, including web addresses "It's hard to work out exactly what the government's definition of web browsing history is," said Alcorn. "It could be extremely narrow or it could be extremely broad." He said NCC analysts interpreted the legislation – which leaves government to specify what metadata consists of – as best as they could, given the lack of precise technical definitions. He added, "Metadata is extremely revealing – it's got a lot of information. It's obvious why it's important to law enforcement."

Alcorn's report reveals the surprising scope of what could be gleaned from the metadata generated by the office outside of its day-to-day dealings with meat and livestock organisations in Australia. "The metadata revealed communication to an airlines booking system and to specific hotels in the Whitsunday Islands," wrote Alcorn. "This may indicate that someone in the office will be travelling in the near future and planning to visit that area of the country." He told Fairfax they can't know that a booking was made, but they spotted what's known as DNStraffic relating to the airline in question and found an IP address for that site consistent with web browsing. "We'd sift through the data and look for interesting things," he explained. "For example, with the airline booking site, we started expanding backwards and forward in time to reveal what other information there is on what the airline bookings might be about. At that stage we found information about the Whitsundays, hotel bookings, etc … it went from airline bookings to hotel bookings and associated holiday information." They found clues suggesting someone was buying furniture – communication to the webpage of a furniture retailer and a subsequent call of four minutes and 12 seconds to the same store. One day there was an interest in jewellery, home improvements and renovations.

Metadata can reveal someone's hobbies or interests without the need to see the content of messages. There was communication in the office with mail servers relating to the Inner West Hunters Club, a NSW approved hunting club. Leyonhjelm is a high-profile supporter of the relaxation of gun laws. NCC analysts referenced other email metadata with public information resources to infer communication with organisations involved in hunting, consultancy, market research and the sale of contact lists for marketing purposes. Metadata could enable future governments to monitor people with agendas other than their own. The potential for inferring links between people, leading to further investigation, is vast. Analysis of sender and recipient email addresses identified people who were often involved in group email discussions. Despite neither subject nor content of emails being available, some inferences could be drawn. Alcorn wrote, "The email metadata collected was suggestive that there was a common political agenda. Taking the email addresses and searching for the people in Google determined they were active in various political arenas. From this information it was possible to find common agendas."

One group email discussion possibly centred around pro-gun reform, with active lobbyists in the area taking part – something NCC analysts determined by putting specific email addresses into a search engine. Other members of the discussion weren't public supporters of changes to gun laws. "An analyst may, rightly or wrongly, infer from this metadata that the other members of the discussion are privately supporting gun reform and for some reason don't want it publicly known," wrote Alcorn. Traffic volume showed when staff were in the office, when they were working late or at the weekend and for how long. Metadata showed consistent spikes of several minutes' activity on Facebook at 9am, around lunch and just before 5pm. One afternoon there was no Facebook activity, which could suggest an early knock-off for the day. Metadata also showed someone was exploring CTP insurance renewal, had used Dropbox – a way of transferring files too large to be emailed – as well as Microsoft, Apple, Nvidia, AVG and Avast technologies. "We're not using the most sophisticated tools to analyse metadata," Alcorn said. "There are faster ways to do it and more automated and mature processes. We also didn't use tools for displaying graphical connections. With further time and more sophisticated tools, more habits and details could be extrapolated."

Metadata is already stored to varying degrees by telcos and was disclosed more than 500,000 times by telcos to law-enforcement agencies in the 2013-14 financial year, according to the Australian Communications and Media Authority's latest report. Attorney-General Brandis said in August there would be a statutory definition of metadata in the bill, which is lacking from the text. Instead, the government will define by regulation what will be captured, citing the need for flexibility to alter the definition as technology changes. That was criticised by the Senate Standing Committee for the Scrutiny of Bills, which last month reported that Parliament should decide: "Whether this scheme – which is highly intrusive of individual privacy – should be applied in a new technological context is a matter which will raise significant questions of policy." The committee also noted that while the bill excludes "content" from metadata storage, it doesn't define what "content" is. It warned: "There is a real risk that personal rights and liberties will be unduly dependent on insufficiently defined administrative powers." Leyonhjelm called the results of the analysis "very revealing".

He had no problems with targeted retention of metadata via a warrant or court order based on suspected criminal activity. "But to collect that data on everyone – my 84-year-old mother and my wife and my next-door neighbours who wouldn't say boo to a goose – it's wrong in principle," he said. He questioned whether it was necessary to collect metadata on everybody when only a very small percentage of it would ever be useful – Alcorn estimated the total in Australia at 32 terabytes a day by 2016, the equivalent of 320,000 albums downloaded from iTunes. "The government's basically saying we're going to spy on everybody in the country," said Leyonhjelm. "It's appalling, it's absolutely appalling." He added, "If you're going to invade people's privacy and treat them all like criminals-in-waiting, then to what extent do you do that? Malcolm Turnbull has said it's nothing more than phone data, to and from and time and location, but it's a lot more than that. I don't see how it can be limited to that and I don't believe it will be, either."