Is it really that big a deal to have the phone numbers connected to the usernames, rather than just having the phone numbers or just the usernames? I can see that someone may have the same username in multiple places, but at least out of the Snapchat users I know, it isn't likely they'd be able to trace the username to a person. Also, people sometimes post their phone numbers on things like Facebook as well, so some of that information may already be public.
Curious how the title of the original article fit into the content of the article as well.