WOW. I just looked at this thread and realize that I got disagreed with and lost points. Doesn't feel fair. I'll try to be clearer.
If you have a solvent client who can usefully be sued (or screwed with by replacing his site with some "down due to non-payment" message), I say go for it.
But, the economy today is really really bad. Many clients signed contracts in good faith awhile ago and today, they are not solvent. They are not making payroll. They are considering filing for bankruptcy. They're in deep hooey. Before you invest lots of time and energy in getting angry. it might not be a guy who has the money. Since contractors tend to be small businesses, we tend not to think about running credit reports up front on our potential clients.
But in many cases, you might be stuck with a client who cannot pay you. In this case, you can enter the legal game and be part of a bankruptcy process (long slow depressing, perhaps lucrative) or you can get on with your life and go find a better way to spend your days.
In my experience, chasing down bad debts has not been a productive exercise. Doing more due diligence on potential clients HAS been productive. And finding new clients has been productive.
Sorry that someone disagreed but frankly, this has been my experience which I thought deserved sharing since so many of today's clients are filing for bankruptcy these days or just quietly closing up shop.