Agreed. And you would think at least some of the journalists would leak evidence of this if they took the integrity of their profession seriously. Again, a lack of evidence isn't proof it didn't happen either.
Some journalists have tried to conjure up "professional standards" that aren't binding, but the fact that they are not binding is why it's not a profession and why those "standards" are just suggestions. Unfortunately, the accumulated cruft of decades of wrongly decided cases grants this pseudo-profession many special rights and no formal duties to counterbalance those.