Media are best understood as a competition for attention on internet-connected screens. Phones, tablets, laptops, monitors, TVs—it's all just glass.

Be honest, do you pay for your own Netflix subscription, or mooch off someone else’s?

A survey conducted by research firm Survata for Quartz found that 31% of Americans who have access to a Netflix subscription do not actually pay for it. Young people are, unsurprisingly, the biggest offenders: 69% of people aged 13 to 17 mooch off someone else’s account, and 50% of 18- to 24-year-olds are moochers.

Survata surveyed 2,255 people in the US in January asking whether they paid for a Netflix subscription or “mooched” by using the account of a family member or friend. Netflix subscriptions allow for one other person to use the same password and login for $8 a month; for $12 up to four people can stream on one account simultaneously.

Sixty-nine percent of those surveyed said they pay for a Netflix account, 26% said they used a family member’s, and 5% said they used the account of a friend.

Survata also found that 37% of males mooch, while only 27% of females mooch.

Netflix, at least publicly, isn’t concerned about account sharing. CEO Reed Hastings called it “a positive thing” at the Consumer Electronics Show in January. Hastings argued that many of the “moochers”—most of whom are young people—go on to become paying subscribers once they get older and have money of their own to spend.

A recent report by Parks Associates estimated that the streaming video industry loses $500 million a year to mooching. Netflix declined to comment.

HBO CEO Richard Plepler is similarly unconcerned about HBO Go moochers. He said last year that password sharing has no impact on HBO’s business apart from being a “terrific marketing vehicle.”

What Hastings and Plepler are likely more worried about is the thriving online black market for streaming accounts, where stolen login credentials are sold at a discount. (Here’s how to tell if and when someone used your Netflix account without you knowing.)

There isn’t yet a clear etiquette for sharing passwords. Sharing within households is fine, and is, in fact, encouraged—Netflix offers a premium family plan that allows streaming on up to four screens at once. Sharing with your best friend or a partner is usually okay too. But what about your uncle? Your mother-in-law? Your buddy’s buddy who really just wants to watch Daredevil and swears he won’t use it again after that?