Perhaps because he put it on radio and television, always giving credit to Breitbart and company, and with their participation. What is your problem anyway?
My problem is everybody on this thread has been giving Beck sole credit for breaking a story he didn't even break. The overall impression given by Beck's viewers on this thread is that he did, which leads people who have not watched his show (such as I) to deduce that he took complete credit for it!
If that's not the case, & Beck is indeed sufficiently crediting the actual reporting elsewhere, then his fans aren't doing him any favors by slighting the reporting elsewhere & making him look like a credit-hogger. They are unfairly (& unwittingly, it would seem) making him look like a jerk.
Beck highlighted the story, that's obvious & he should be credited for that, but he wasn't the only one out there doing so.