Update 2018-02-04: See Rick Perlstein’s  and Henry Farrell’s  Op-Ed in the New York Times: Our Hackable Political Future . TL;DR: falsified video/audio of real people is here, and people aren’t ready for the implications. Anything you see on a screen isn’t evidence anymore.
Update 2017-01-19: After I wrote this post, I read Thomas B. Edsall’s excellent What Does Vladimir Putin See In Donald Trump?  in the New York Times, and realized that faked kompromat against credible politicians who oppose Trump is even more likely than against Trump himself. So, er, watch out for that too. I can’t even describe how depressing that is to contemplate. Imagine, say, Tim Kaine’s or Cory Booker’s potential run in four years being headed off by a faked video of him accepting a bribe. The only countervailing forces I can think of are 1) good investigative journalism, and 2) the fact that fake kompromat still has to be believable to be effective — which is why Trump is so especially vulnerable to it.
I don’t think the Russian government installed Donald Trump as President — American elections aren’t that easy to control. But as Louis Pasteur allegedly said: “Chance favors the prepared mind.” Russia got lucky, but also knows how to play a good hand when dealt one.
What would you want right now if you were Vladimir Putin?
Something like this: a weakened, delegitimized, and more easily manipulated Donald Trump being sworn in as President on Friday. Ideally, a Donald Trump who does not necessarily think that whatever weakened him came from Russia, but who thinks that Russia might have worse stuff in the dumpster out back (worse stuff than lopsided business debts to state-affiliated Russian oligarchs, that is, which is what I’m guessing Trump has in his dumpster out back).
With rumors of video clips now already in public discussion, Russia — or really any party with access to skilled and discreet technical talent — is now in the perfect position to release a video tape of Donald Trump that shows whatever the heck they want.
The age of widespread faked kompromat  has arrived.
Unfortunately, it will start with an ugly interim period in which realistic digital video is fakeable but most people still believe that video footage represents reality. The technology to produce convincing fake video and audio has not yet become available to the average computer user, so people aren’t yet accustomed to discounting what they see with their own eyes and hear with their own ears. (It’s just a matter of time; expect open source code modules for it pretty soon.) This weapon of misinformation is already available to any well-resourced state actor, however. Know anyone whom that description fits?
At any time, starting now, someone could leak a video that convincingly shows Donald Trump saying anything they want him to say  (update 2017-07-18: they can fake it even better now ). Or, as the case may be, they can show him doing anything they want to show him doing.
Will people think he really said or did those things? Ah, that’s the beauty of a politician like Trump: he’s so outrageous that people will believe anything about him, and he’s such a chronic liar that his own protests will not carry much weight even with his supporters. Denial’s difficult when you have no credibility.
It would be illogical not to take advantage of this opportunity; let us assume someone will behave logically. It doesn’t have to be Russia, but Russia has the right combination of access to technical skills, experience, motivation, comfort with this type of tactic, and reasons to be confident that those involved will never breathe a word of it to anyone on the outside.
The days right before or right after inauguration would be a good time to do it. Just sayin’.
I’m not sure there’s anything we can do about this, even if we know it’s coming sooner or later. Just sit back and enjoy the production values, I guess. Here in the U.S. that’s how we’ve often reacted to our military deployments, particular those involving laser-guided missiles and other high-tech things that go boom. Isn’t it time we learned to appreciate the subtler but no less exacting attention to detail required to produce high-quality fake kompromat?
This is not going to be fun :-(.