Fast & Furious was a scandal (albeit a small one). There's a couple of other posters that outline things that should have been scandals but it's not that the media never reported it, it's that the public didn't get outraged.

Not enough people cared about the extra-judicial assassination of a US citizen because he was probably a terrorist so it only lasted one news cycle, that could have been a scandal but it was not. If people don't care about the behavior as being wrong then the event won't be a scandal.