Transcript for Man charged with hacking photos from teens' Snapchat accounts
We are back with new concerns about privacy and Snapchat after a New Hampshire man was arrested for hacking into the accounts of teenage girls posting their pictures online. ABC's Eva pilgrim is here and this is not an isolated case in no, pretty much every social media outlet has been hit. Hackers should make you think twice about what you and your kids have on social media. Even things you mark as private aren't so private when a hacker finds his way into your account. This morning, a man behind bars charged with hacking photos from teenage girls' Snapchat accounts and reposting them on the internet himself. Police say 21-year-old Michael tsarni swiped them from several teen girls in Wyndham, new Hampshire. When the photos they thought would disappear from the app reappeared online, one of the victims went to police. She recognized that the account had been logged into somewhere that she was not. Reporter: Snapchat allows users to share photos and videotapes that are supposed to disappear in less than ten seconds or you can post content that is automatically deleted after 24 hours. Snapchat is a very secure social media site and it takes somebody really knowing what they're doing to actually be able to hack into another person's account and take pictures. Reporter: This the latest case where a hacker reposted stolen pictures. In September, a 17-year-old Washington high school student was arrested after a classmate reported her social media accounts were hacked. The hacker allegedly found nude photos she kept in a private section and shared them with other students. We definitely want to make sure that people like that that are preying on other people via digital means or the internet are arrested. Reporter: Experts warn think before you post. And make sure your accounts are secure. Make sure your privacy settings are locked down and of course the password, it is a small thing but it can make a big difference between whether or not someone has access to your account or not. Reporter: And police are not saying how he allegedly got into the Snapchat accounts or what type of photos were stolen and while he is facing charges that cannot undo the pictures that have been seen on the internet. We have reached out to Snapchat. They would not comment on the case. When you look at this we have seen so many cases like this. You have to assume if you post a picture on the internet it can get out. We tell kids that. We tell each other that as adults and you still see grown-ups and kids taking pictures on their phones and posting them even privately. Anything that is on your phone, anything on social media did at risk. Just don't do it. Real secure passwords can help a bit. He can help a little bit but you have to remember anything you send to somebody you risk them taking a picture with another phone or snapping a picture on that phone there so it's all a risk any time you send a picture like that. I'm a believer, once it's out there, it never goes anywhere. Thank you.
This transcript has been automatically generated and may not be 100% accurate.