I think people are overreacting to the whole "giving away her personal information" part of it. The article says that Mailloux "also sent a screenshot of the victim’s online profile, which identified her to teammates by displaying her photo, first name and age". I don't know how many of you guys are social media savvy in here, but this sounds a whole lot like an Instagram profile, which would make sense, because the screenshot would include her username, profile pic, maybe three photos she has on her page, and her bio, which would include her name, age, and maybe other info depending on what the person wants to share. I don't think sharing the person who you just hooked up with is something weird or unnecessary to do, especially with Instagram, as their Instagram profile is already open to the public. It is not as though these kids are getting her phone number and making unnecessary comments to her in private conversations. For any teenage guy or teenage friend group, people obviously want to know and are curious about the girl their friend just scored, and sending their friends the girl's public Instagram account is the easiest way to do so, given that it is already public. I guarantee that whatever girl that got with Mailloux shared that exact info with her friends about Mailloux. It's not abnormal; when someone you are close with gets intimate with someone else, you of course want to see who it is and how well they did.
Is doing this enhanced by the photo? Yes. But sharing a profile after hooking up with someone is a normal thing to do. Some of the teammates probably already knew who the girl was before the whole incident happened because Mailloux probably mentioned that he might be hooking up with this girl beforehand and had more than likely been talking to her for a while at that point. And even if you only knew the girl by name, Instagram is public, so his teammates probably could have found her in a grand total of 5 seconds if he hadn't shared the profile, which they more than likely would have done.