Have they lightened them recently?I notice that the 7 HD Digital watermark is almost see through now and I vaguely remember them being solid white.I know a few months back there was an uproar over image burn on newer HD TV screens and I'm guessing this is the result.
Initially the networks were telling people to adjust the contrast on the set,which IMO stunk.The image was burning into the screen so the networks wanted us to make our picture crappy so the precious watermark wasn't offended.
EDIT:Just looking and 9,10 and SBS still seem to have a more solid watermark.
The ABC is the faintest and ABC HD & ABC2 have no watermark at all.