Alexander McFadyen says that he and his family were “more or less constantly watched” while they were at home. They had to be “properly dressed” at all times, and even then they were often photographed or filmed, and sometimes spied on with binoculars. McFadyen set out to measure the problem. While working at the dining table, he counted 84 people taking photographs in 90 minutes.

This is the reality of living in a glass-walled flat in Block C of Neo Bankside, just 34 metres from the viewing gallery at Tate Modern, which receives up to 600,000 visitors a year. A neighbour, Claire Fearn, said being watched like that made her “sick to her stomach”. People waved and made obscene gestures at her and her family. Her husband, Giles Fearn, found pictures of their home posted online by strangers. Many of the images are still on Twitter, often with amused remarks about the misfortune of their wealthy owners. (The flats are worth an average of £4.35m each.)

Another neighbour, Lindsay Urquhart, visited the viewing gallery and heard someone remark that she and the other residents of Block C deserved to lose their privacy because they were “rich bastards”. A high court judge recently denied five residents’ request for part of the viewing gallery to be closed. In his judgment, Mr Justice Mann ruled that “the claimants are occupying a particularly sensitive property which they are operating in way which has increased the sensitivity … No doubt there are great advantages to be enjoyed in such extensive glassed views, but that in effect comes at a price in terms of privacy.” He suggested various solutions, including the one already put forward by the Tate’s former director, Nicholas Serota: net curtains.

Whether or not you consider them rich bastards, you have to sympathise a little with the McFadyens, the Fearns and the other residents of Block C. Not many people would like to be filmed in their pyjamas, yet the bright apartment space with rooftop vistas is the great fantasy of city living, the sort of thing that people become rich in order to enjoy. Is it only a fantasy?

“The law has traditionally regarded the home as a zone of privacy meriting special protection,” Mann said. On the other hand, he added that “an occupier in that environment can expect rather less privacy than perhaps a rural occupier might. Anyone who lives in an inner city can expect to live quite cheek by jowl with neighbours.”

In the UK, disputes like this would ideally be prevented by the planners, who can require obscure glass to be fitted in windows that would otherwise look into people’s homes. In this case, however, the Tate extension and Neo Bankside went through planning at similar times, and it seems that the overlooking implications were, well… overlooked. The Human Rights Act gives everyone a right to privacy, but only when it concerns infringement by government bodies, which the judge ruled does not include Tate Modern.

That leaves only the law on nuisance, which more often applies to noise or dust or smells, but can cover invasion of privacy. “We all have to put up with something,” says Jason Hunter, a lawyer at Russell-Cooke, who works on nuisance cases. “The question is, when does an indeterminate line get crossed? When does it move from something that we have to put up with to something that we don’t have to put up with?” Yes. When? “That’s the question that I’m always asked. Where is that line? It’s very, very difficult.”

In cities there are traffic cameras, congestion charge cameras, car park cameras. Photo: Shutterstock

Cities getting less private

And of course the line moves, as cities become less private than they used to be. Seeing more people means more people can see you, including the city authorities. Your swipe card keeps track of your movements around a public transport system, and you will usually be filmed in buses or trains, and in the station. If you drive, you’ll probably be recorded by traffic cameras, congestion charge cameras, car park cameras.

In New York, the Citibike scheme shares its journey data publicly, including the gender of each cyclist, and their year of birth. And of course there’s Google, which regularly photographs your home, both from the street and from the sky, and makes the pictures available online. In many Chinese cities, and even in villages, your face could be photographed, recognised and monitored by the government’s Sharp Eyes programme.

Inside the home, smart meters record your energy usage, potentially revealing when you are in, and when you are awake. Many people have voice assistants, such as Amazon’s Alexa or Google Assistant, which record some audio in their homes, and may yet yet do much more. You can be watched by drones in your back garden, or even through your windows, and it isn’t yet clear where the law would stand on that.

In April 2016, Singapore experimented with motion sensors in some state-run old people’s homes. These were supposed to alert families if their relatives stopped moving around, even if they stopped using the toilet. The trial ended quickly, because the old people didn’t care for it. Stories emerged from another project where they’d simply covered the sensors with towels.

Some people are alarmed by loss of privacy, others hardly care. If it must be collected, some want their data to be held with the utmost security, others prefer the openness of public access. Different cities around the world, including Barcelona, Amsterdam and Seattle, are drawing up different rules to govern the issue. Over time, it is not even possible to say whether privacy will feel less important, as citizens learn to live with less of it, or more important, as we become increasingly aware of how little privacy we have left.

If it’s any comfort, this uncertainty is not new. In 1906, the architect Baillie Scott lamented the large windows which had begun to appear in private homes, “arranged, like a shop is, for outside effect”. In 1929, Walter Benjamin rejoiced in the opposite. “To live in a glass house is a revolutionary virtue par excellence,” he wrote, arguing that it would dissolve the aristocratic and bourgeois “discretion concerning one’s own existence”.

So which is it, now that we’ve had a century to think? Are big windows an odious exhibition of wealth, or a repudiation of bourgeois privacy? I suppose we get to blame rich bastards, either way.

By Leo Benedictus