SEATTLE • In the middle of a long bicycle ride several weeks ago, I pulled over for a rest and took out my iPhone to send a text message to my wife. I had a feeling she might be watching me.
"If you're checking my location, I'm not dead," I wrote to her. "I'm getting coffee on Mercer Island."
As it happens, she was not keeping tabs on where I was, but she could have - and has in the past - because I have allowed her to do so using the location-tracking capability in my phone.
Whenever she's curious, she can see me represented as an orange dot on a digital map on her phone. An unmoving dot could be a cyclist husband who got a flat tyre, grabbed a beer with a friend or was hit by a car (hence the reassuring text).
Now and again, I, too, check my wife's location, so I know when she leaves work and can time dinner with her arrival. She and I have both tracked the whereabouts of our 13-year-old daughter using her phone to reassure ourselves that she was on her way home from school or a trip to the store.
When did you start working for the National Security Agency, I've asked myself in jest.
Most Americans don't like the idea of their government spying on their Internet activities, and a lot of them have misgivings about companies tracking their online habits for commercial purposes. But when they are presented with the tools and opportunity to play Big Brother with others in their family, it's tough for some to resist.
I'm not just talking about family members who register on the creepy-stalker side of the spectrum although there are certainly jealous spouses and overbearing parents out there who surveil their partners and children with an unhealthy vigilance.
Digital monitoring - from tracking those whom loved ones communicate with to snooping on their social media accounts to checking their locations - is becoming common even among people who view themselves as mindful of the boundaries with their children and partners.
Is there such a thing as responsible spying on loved ones?
We're moving closer to a world in which parental surveillance becomes opt out instead of opt in.
MS MARY MADDEN, a researcher at Data & Society, a non-profit research organisation.
The answer depends on whom you ask. Strong believers in privacy reject the premise of the question outright while others believe it is possible if consent, trust and respect are involved.
"It comes down to power dynamics," said Ms Mary Madden, a researcher at Data & Society, a non- profit research organisation. "You can imagine a scenario where, in a family, it's an unhealthy dynamic."
Parents now routinely keep tabs on their children's digital behaviour in one form or another. A Pew Research Centre survey of adults with children 13 to 17 years old published this year found that 61 per cent of parents checked the websites that their teenagers visited, 60 per cent visited their social media accounts and 48 per cent looked through their phone calls and messages. The portion that tracked their teenagers' whereabouts through their cellphones was 16 per cent.
"We're moving closer to a world in which parental surveillance becomes opt out instead of opt in," Ms Madden said.
The prevalence of parental tracking is the logical outcome of a world in which children spend so much of their lives in the digital realm, for entertainment, communications and information access. Smartphones and tablets, the advent of social media and the explosion of newer forms of communication like texting have made digital technology an even deeper part of the fabric of adolescence.
As these digital phenomena have proliferated, so too have tools for controlling access to them for health and safety reasons. Since the 1990s, start-ups have pitched filtering software to parents for preventing their children from seeing sexual content and other material.
Then smartphones came along, and the major wireless carriers began marketing services for controlling access to content, apps and those whom children could communicate with, along with tools for tracking a phone's location using the wireless communication chips in the devices.
One carrier, T-Mobile, says it has four million customers using a free service that blocks their children from viewing sexual content, graphic violence and crude humour. It also has 375,000 customers who pay US$4.99 (S$7) a month for something called Family Allowances, which lets parents block their children from texting and calling certain phone numbers, shut down their phones during school and homework hours, and monitor how much they are texting.
T-Mobile has about 100,000 subscribers who pay US$9.99 a month for another service, FamilyWhere, which lets families keep track of the location of all phones on their accounts.
More recently, phone makers like Apple have made capabilities like family location tracking even more accessible by building them into their phone software-free. Activating the function on an iPhone also helps one locate a misplaced device.
One danger of these technologies, of course, is that many parents will be tempted to overuse them, and in intrusive ways. A parent who constantly micromanages a teenager's life - Why did you stop here? Why did you go there? - risks stifling the independence needed to develop into an adult.
Mr Lee Tien, a senior staff lawyer at the Electronic Frontier Foundation, a non-profit focused on online rights, is among those who are sceptical about digitally monitoring children.
"It's really hard for me to imagine that a parent who had been trying to be rational and understanding would do that," said Mr Tien, who has two children in their 20s. "My approach to parenting is at a certain point, long before the age of maturity, you treat them like adults."
Dr Danah Boyd, the founder of Data & Society and a visiting professor at New York University, said that sharing digital information, including location, is viewed as a sign of trust and respect between people with close relationships but that it can be easily twisted into an abuse of power.
"The game changes when we're talking about a 16-year-old who feels 'stalked' by their parents," Dr Boyd wrote in an e-mail. "This is because the sharing of information isn't a mutual sign of trust and respect but a process of surveillance."
In her fieldwork with teenagers, she said, she was disturbed to find that the privacy norms established by parents influenced their children's relationships with their peers. Teenagers share their passwords for social media and other accounts with boyfriends and girlfriends.
"They learnt this from watching us and from the language we used when we explained why we demanded to have their passwords," she said. "And this is all fine, albeit weird, in a healthy relationship. But devastating in an unhealthy one."
The same goes for adult couples who use digital technologies to keep tabs on each other.
In my case, it has a mundane use.
My wife and I have found that tracking each other's locations makes some of the logistics of busy family life easier and safer. We don't need to text each other from our cars to say we're on the road, except if one of us makes an unplanned stop, as I did.
Ms Sarah McQuade, a stay-at- home mother in Kittery, Maine, worked out a similar arrangement with her boyfriend, who lives about 32km from her. They use an app called Glympse that allows people to share their locations for defined periods of time.
When her boyfriend drives to see her, the app lets her know he is still moving, especially on treacherous winter roads. "If you're doing it for verification purposes instead of safety and convenience, then maybe you need to rethink why you're using it," she said.