As a freelancer in Sweden I can't even imagine how big I would have to fuck up for a customer to sue me for anything beyond what they had already paid me.
Imagine you are paid $100 to build a website to sell some new widget to be delivered on November 1st just in time for the holiday season. The company also spends $1000 on a one-day internet marketing campaign that's around the launch.
Then there's a technical issue at launch and orders are being rejected left and right.
They could be out basically the whole value of the marketing campaign which is 10x your salary. You might owe them compensation for that, unless of course you got paid through an LLC and only have the $100 in your account.
And if you have any sense, the contract expressly limits your total liabilities to the client to at most what they have already paid you.
(ps. With some careful lawyer drafting to exempt things which can't be limited in that way (negligence etc.), while carefully wording the exemption so any part voided doesn't take the whole limitation with it.)
In the US lawsuits typically open with the closest thing a lawyer can imagine to infinity dollars of damages, and then you have to have your lawyer work it down.
