Fairfax journalist Ben Grubb. I thought it made a great story – a flaw in the system that meant not everything you uploaded to social networks was secure, even if placed behind a privacy-protected profile – and the yarn was published on Fairfax's news sites yesterday. Hours later, Coultis's phone call came completely out of the blue. I walked out of the session and met him and his female offsider about 4.15pm, and, at my request, we went into a meeting room to discuss the matter in private. They told me they were recording the conversation. I had my wits about me enough to ask if I could also record the conversation; Coultis agreed and so I pressed record on my iPhone. For about half an hour I stood in this room – its only adornment dozens of green chairs stacked against one wall – and co-operated with what Coultis and his colleague described simply as "questioning" over the incident. I was reassured when he said he had no intention of arresting me and I agreed to help with his inquiries. Neither of them wore police uniforms – their casual clothes, including Coultis's AusCERT-branded T-shirt, comforted me further.

The officers were polite and there was even an amusing interlude when the female officer's iPhone rang, disrupting her recording of our conversations, and I gave Coultis some advice about how to set the iPhone to avoid further interruptions. They seemed to treat me like a technical expert, and sought my explanation of what Heinrich had done. I felt like they were trying to get me to admit that his actions were illegal. I told them it was not my job to decide that – after all, I was only reporting on the matter. It's their job to decide whether what he demonstrated was against the law. About half an hour into the questioning, Coultis left the room to liaise briefly with other officers. When he returned, he said: "What we're going to have to do, I'm afraid, Ben, is we're going to be taking possession of your iPad." Now, anyone who knows me knows that my iPad and I are inseparable. As a technology reporter and a 20-year-old who has lived and breathed gadgets, my life is played out in tweets and Facebook posts. This device had become the centrepiece of my life – it's integral to my work because it's where I keep notes about stories, but it's also the digital tool I use to run my social and personal life. When I questioned under what legislation they had the right to seize my iPad, Coultis told me I was under arrest in relation to receiving unlawfully obtained property.

What? What I had thought had been a simple case of answering some police questions had suddenly taken a turn for the worse. I felt as if I had been double-crossed. It seemed ridiculous that I, as the "messenger" who reported on what the police were now saying was a criminal matter, could now be the target. Feeling shaken but with the adrenalin pumping, I phoned my boss and tried to contact lawyers. It was another one of those odd TV moments, when you're given the right to make a phone call. I did that, but being a Gen Y, I also tweeted the fact to my 5000 Twitter followers that I had been arrested. Another hour of talking ensued, but now I was under instruction from my lawyers to keep my mouth shut. The officers spent much of the time on the phone to my boss and the lawyers, explaining why I was being held and what charges might be laid. At one point, they mentioned that I could be held legally for up to eight hours. Throughout this, my phone did not stop ringing and buzzing as the Twitterverse took up my case. Hundreds of tweets were directed my way and to the Queensland Police media unit, questioning why a journalist had been arrested and sending me messages of support. At one point, when Coultis accompanied me to the toilet because I desperately needed to go, I showed him the responses.

Shortly before 6pm, I was given a receipt for my iPad and Coultis told me that I was "un-arrested". I was free to go, but, to the best of my knowledge, my iPad remains at an exhibits facility in Brisbane. I was told that forensics officers were going to make a complete copy of the information on my iPad, whether it related to this matter or not. I feel like I have been unfairly targeted. Journalists must be able to report what they observe – that's what they've been doing for ages and so to see this kind of policing occurring is very alarming. I believed that, as a journalist, I had protections. But it seems not. And to lose a device that contains not only private but work-related information is also another seriously alarming development for a journalist. Loading This reporter is on Twitter: @bengrubb