I've written columns on news fakery the past two weeks. In response to last week's column, where I talked about video fakery, reader Jim May emails:

"In a recent TCS Daily column, you wrote the following:

"'So far, video-photoshopping isn't as common as fakery with still photos, but as the tools for that improve, we'll see that, too.'

"I am a visual FX artist working in Hollywood (recent credits include 'Serenity', NBC's 'Surface' and as of tonight, 'Beerfest'). I make fake images, moving AND still, for a living. I have the tools required to do precisely this sort of thing installed right here on my hard drive now. Your prediction is essentially correct, at least as regards political dirty tricks; beyond that, such fakery has been going on for a decade or more, now."

He's right, and the accumulation of episodes of fakery in recent weeks, both sophisticated and crude, leads me to believe that we'll see faked video of professional quality becoming a commonplace political item in the pretty near future.

And this poses a significant problem. In a democratic polity -- or even one that's driven by things like "world opinion" -- faked news poses a real threat to decent decision-making. Worse yet, the likely outcome of widespread fakery will be a tendency on the part of people to simply dismiss news that they don't want to hear. (And we already see enough of that phenomenon as it is).

I wish there were a technical solution to this problem, but that's probably pretty far away. May sent me a link to the Columbia University TrustFoto project, which is aimed at detecting fake still images. So far, it's not very good -- I gave it an obvious fake and got a rather inconclusive response. It's a great idea, and the technology will no doubt improve, but will it ever be good enough to reliably distinguish between genuine and phony images? Not anytime soon, anyway. And identifying phony video is probably even harder.

Once again, as I've said in previous columns, it boils down to whom you can trust. And although it seems that Big Media outfits, which want to make money and be around for the long term, would have a sufficient investment in their credibility not to fake news themselves, or to pass along fake news except in extraordinary circumstances, the evidence of recent weeks is that journalism is rife with fakery, and that we're seeing more of it now mostly because it's easier to spot now that lots of people can examine the evidence and compare notes.

And maybe there's a lesson there. A recent kerfuffle over allegedly faked photos of Congresswoman Jean Schmidt finishing a marathon turned out to be bogus: The picture in question was genuine, as was clear after analysis. But blogger Matthias Shapiro wasn't impressed with all the photo evaluation, emailing:

"It turns out Rep. Schmidt has run dozens of marathons and posted some very impressive times. Given this context, why would she fake a photograph of her finishing a marathon when she probably has hundreds of authentic photos of her finishing other marathons? I suspect that this is much ado about nothing and will end up being something of an embarrassment to those involved... an embarrassment that could have been avoided if the critics had done that 20 minutes of research and judged the photograph in the wider context of Rep. Schmidt's biography. (Incidentally, it is this very examination of context that helped to discredit many of the fauxtographs shot by the friends of Hezbollah.)"

Context is key. And one of the lessons of these various affairs is that neither the photo, nor the purveyor of the photo, should be given unquestioned authority. Instead, we have to think for ourselves, and make up our own minds. Because it turns out that we can't trust, well, much of anyone.

You can hear me discuss these issues further with bloggers Charles Johnson and Dean Barnett on this TCS Daily podcast. And yes, that's really us -- not faked voices. Trust me.

Glenn Reynolds is a TCS Daily contributing editor.