A lot of people — myself included — see Western Union as one of the companies most vulnerable to disruption by Bitcoin. Western Union allows people to send money around the world, but it's somewhat slow and expensive. Bitcoin boosters say their technology can do the same thing faster, and for a fraction of the price. One Bitcoin enthusiast made a graphic to illustrate the point:

Now another Bitcoin enthusiast, Dave Aiello, is reporting that when he posted this image to his Facebook page, he was hit by a copyright claim from Western Union. Copyright law gives sites like Facebook a strong incentive to comply with these requests by taking down the image, and according to Aiello that's exactly what Facebook did.

Yet there's a strong argument that using Western Union's ad in this fashion allowed by copyright's fair use doctrine. That doctrine allows the use of images for purposes of comment and criticism, and here Bitcoin supporters are clearly criticizing Western Union — and the company's ad — by pointing out Bitcoin's technical advantages. This is precisely the kind of situation the comment-and-criticism exception was designed for.

It's worth noting that this ad overstates Bitcoin's advantages over Western Union. It's true that you can transfer funds from one Bitcoin user to another with very low fees. However, for the system to be useful to ordinary people, there needs to be some way to convert from conventional currencies to Bitcoin, and back again. Right now, the fees for this kind of service often makes Bitcoin-based money transfers as expensive as — and more cumbersome than — Western Union. There's good reason to think these fees will go down over time, but they're unlikely to ever be as low as a penny.

In any event, the takedown request, and the resulting controversy, will only make the image more prominent — a phenomenon known as the Streissand Effect. People like to read about controversy, and so discussion of the takedown request will bring the image to many people than would have seen it otherwise.

Western Union hasn't responded to emails seeking comment on the story.