How exactly does a writer go on strike?

It's quite hard to imagine a writer aggressively deciding not to write anything.

After all, it's what most of us do all the time. Here I am, posting on the Internet when I ought to be writing. Maybe I'd feel better about it if I told myself that I was on strike.

But writers in the States are on strike at the moment. We won't see much immediate impact on this side of the Atlantic (not yet), but a television and film industry without writers can only last so long. And the Writers' Guild of America have an extremely efficient old-fashioned closed shop. If you're not in the WGA, you don't get work. And if you break the strike, you'll never work again.

So, the more interesting question is not "how?", but "why?".

Here's a little video the WGA prepared earlier. Well worth three or four minutes of your time...