We buy security cameras to protect our home from robbers, see who is at the front door—and apparently spy on our kids. So says a new study, released today, from home security firm Blink which found that one in five would use a secure monitoring system to watch their children—and not tell them.

With school starting in some states this week, Blink surveyed 16,839 adults as part of its "Back to School Home Security" report, to see what parents think about their children coming home to an empty home—and how they feel about checking in on their kids.

Blink found that of those whose children were home alone after school, nearly 18 percent wanted to make sure their kids were getting their homework done, and perhaps not kicking back with Pokémon Go.

While nearly 22 percent said they would both tell their kids they had set up a security camera and show their children where the device was located—almost 23 percent said they wouldn't tell their kids either detail. And actually tuning in to watch their kids? Just one-quarter of those surveyed said they would enjoy watching real-time videos of their kids while they were at work or away from home.

Babysitters? Not surprisingly, parents trust the nanny far less than they trust their own kids. Almost half of the respondents would absolutely use a Nanny Cam—and one-third of said they wouldn't tell the babysitter there was a security camera in the house.

Home security systems are one of the first smart home devices that consumers buy. They're often considered the gateway device as a security camera—part of a home security system—can be viewed as a simpler product to install. Indeed, nearly nine out of every ten people surveyed said they would use a home security system, but a staggering 62 percent said they wouldn't attempt to set up a home system on their own, with more than one-quarter say they'd actually be too "intimidated," according to the survey.