I think I could disappear if I had to. Like most journalists who have worked overseas in countries with authoritarian regimes, I have always been vaguely conscious of being under surveillance. That awareness grew when I met Edward Snowden in Hong Kong, along with colleagues Laura Poitras and Glenn Greenwald, in 2013. I was not paranoid then. I am now, at least a little bit. As a result of the Snowden revelations, I would have no hesitation about leaving all electronic communication devices behind. It’s also helpful that since my teenage days I have regularly disappeared into the Scottish mountains, sleeping out in the open, under bridges, in caves and bothies.

But Brett Lovegrove is sceptical – and he is in a good position to know, as former head of counterterrorism for the City of London police, and as lead investigator in Channel 4’s Hunted. The surveillance reality show, whose sixth and final episode goes out on Thursday, let 14 members of the public loose in the UK to see if they could evade capture for 28 days. Each was given £450 and an hour’s notice. Could they evade Lovegrove and his 30-strong team of former police, security officials and an ex-CIA analyst who helped hunt Osama bin Laden? Going into the final episode, only four of the 14 are still on the run. Can they hold out just a little longer, beating the UK’s pervasive surveillance network? Or is there nowhere left to hide in Britain in 2015?

Lovegrove has been watching with amusement many comments on Twitter and elsewhere from viewers boasting about how, unlike some of Hunted’s more hapless fugitives, they could evade capture. It is just not that easy, he says. Technological surveillance – tens of thousands of CCTV cameras, automatic numberplate recognition on motorways and other major roads, data from our smartphones, the UK’s estimated 69,000 cash machines or posted to social media – is making it easier and easier for the police and security services.

On top of all this is basic human weakness. “You can escape from the authorities but not yourself. People do not realise the psychological pressure they are placing on themselves. They become paranoid. So when people say they can get away for a month, I smile,” Lovegrove says. “The only people who can do it are those from the police, the security services and the military who have been specially trained.”

Hunted has shown that in this hyper-connected world it is is almost completely impossible for us to be 100% private Emma Carr

The programme opened with a doctor from Kent heading by car for the Scottish Highlands. He is eventually caught. Two women opt for the tactic of hopping on and off buses, but are spotted by a station camera on their 21st bus. Two other women from the first episode – Emily Dredge, owner of an online company, and her friend Lauren English, a decorator – head off on an erratic journey hitchhiking around England.

In that first episode, Dredge complained about the level of intrusion after investigators raid her home. “They’ve gone through my knicker drawer. They’ve gone through my bins. They have gone through my fridge. My phones and family phones have been tapped. My bank accounts have been looked at. My internet has been looked at. Every message I have ever sent on my phone has been read. Every email I have ever sent or received has been watched. My whole life is completely under surveillance,” Dredge said.

In spite of that, both she and English go into the final episode still at large. The other two on the loose are Martin Cole, an IT specialist, and Stephen Hardiker, a heating engineer, who have managed to stay off the grid by cycling and camping wild.

For some, the programme – which has attracted an audience averaging 2.4m – has been purely entertainment, a fun reality show. One tweet said: “Would you not just go and hide in Ikea? Everybody gets lost in there.” For others it is more serious, a way to highlight issues raised by Snowden about privacy.

Emma Carr, director of privacy campaigners Big Brother Watch, says: “We hear so much about the various ways that we can be put under surveillance, but for many people it is difficult to understand how that would work in practice. Most people believe they have nothing to hide and, therefore, nothing to fear but Hunted has shown that in this hyperconnected world it is is almost completely impossible for us to be 100% private.”

Click here to see a trailer for the final episode of Hunted.

Dom Bird, head of formats at Channel 4, who commissioned the programme from Shine TV, says discussions about a second series are ongoing. The US network CBS is also planning an American version. Bird says the concept was inspired by the debate over privacy, the snoopers’ charter and technological change, especially the advent of the smartpone. The would-be fugitives in Hunted demonstrated how much life had changed over the last decade. “Being able to stay away from mobile communications is now almost impossible,” Bird says.

Police and security sources independently confirm that the techniques they use are near-identical to the ones on Hunted. What Lovegrove’s team could not do is access street CCTV cameras. The programme-makers got around this by having a team in the middle who acted as a buffer between the fugitives and the hunters. Whenever a fugitive passed a known CCTV camera the buffer team would, after a time lag, inform the hunters.

We will know you are from Scotland and that you feel safe there. It is hard for humans not to be predictable Brett Lovegove

Lovegrove is dismissive of my plan of escaping into the Highlands. He says that being on the run is very different from being in the mountains for recreation. “You would have been relaxed then. You would have had a support network. If you went into a village, you would not have been worrying.”

He adds: “What you would need to do – even if you abandoned all technology and used a bike – you would need to have three to four months not using technology beforehand. You would have been using it unwittingly until the day you leave and say, ‘Bye darling’. You would have left a footprint. We will know you like climbing and are from Scotland and that you feel safe there. We might even intercept you on the way. It is hard for humans not to be predictable.”

So why then are there still “most wanted” lists? The National Crime Agency and Crimestoppers list people wanted for alleged murder, rape, fraud, insider trading, cannabis production and other suspected crimes. There is no total for the number at large – each regional force has its own list – but police say some fugitives only appear on the list for a day or two before being caught, and that some are fugitives living abroad or criminals from other countries who might have come to the UK.

Daniel Cuthbert, chief operating officer at SensePost, an ethical security-tester and an expert in digital surveillance, says it is possible to disappear. “It is doable, but it is bloody hard. Snowden has shown that. You would have to get off the grid. Stay away from public transport and CCTV.”

Other tips: “Stay away from big cities. The idea is that you can hide in the noise of the cities, but there are so many CCTV cameras in London. If you use a disguise, it is OK for a short time. Another option is to stick to using cash, not a credit card. But it is difficult. If you want to rent an apartment, they would want a credit card. Even if you want to rent just a room, they would want to do a background check,” he says.

What about hiding in the mountains? Cuthbert says it would be hard, especially in the winter. “I would move to rural communities, find a friendly farmer, do labouring jobs under an assumed identity. A lot of people on the run use a bartering system.”

Although GCHQ and Britain’s other intelligence agencies complain that the Snowden revelations damaged their surveillance capabilities, they have developed even better techniques since he leaked the documents. And technology is becoming even more sophisticated. Bruce Schneier, one of the world’s leading computer security specialists, wrote in Forbes last month about advances in facial recognition. “Walk into a store and the salesclerks will know your name. The store’s cameras and computers will have figured out your identity and looked you up in both their store database and a commercial marketing database they’ve subscribed to. Walk by a policeman, and she will know your name, address, criminal record and with whom you routinely are seen.”

Snowden broke all the basic rules for fugitives. He flew to Hong Kong and checked into a hotel under his own name. He paid his bills by credit card. Lovegrove and his team could have tracked him down in a nanosecond.

But Snowden offers hope to Hunted’s escapees. His experience in Hong Kong and subsequent exile in Russia shows that state surveillance is not yet omniscient. After his revelations, Snowden fled his room at the Mira hotel and went into hiding at still-unknown locations around Hong Kong. There is still luck. The accidental. The human error. In spite of all the advances in surveillance and the forces directed against him, Snowden remains at large, the world’s most famous fugitive.