I DON’T KNOW HOW MUCH THIS MEANS, but reader George Dunham notes that Viacom stock seems to have taken a modest tumble today. Could there be a reason other than the troubles at its CBS holding? Note the sharp drop just before 3:00.

UPDATE: A reader says that Viacom has other things going on that might affect the stock price. I won’t bother to list them here, but of course that’s entirely possible. It’s also suggested that putting the announcement off until 5 is designed to let bad news hit after the market closes. Could be.

ANOTHER UPDATE: Related thoughts here, from Professor Bainbridge.

MORE: A reader emails:

This is my train of logic:

1. Once CBS admits that these were forgeries, then there is no journalistic ethic preventing them from naming the source of the documents — actually the source should be exposed.

2. As long as CBS is “investigating” the documents, then they haven’t admitted to the forgery and they can protect their source’s identity.

3. Therefore, the source is so politically explosive that it’s worth the permanent damage to their brand and their news credibility. Who or what could possibly be worth that?

Janet Tague, Stamford CT. Not a political operative. Actually a registered Democrat (although I voted for Bush last time and most certainly will again now).

There’s a lot of that going around all of a sudden. . . .