Patrick is right about not taking self-help measures such as shutting down their site.
Check your contract:
+ The contract might provide that you have the power to terminate the deadbeat client's rights in the deliverables (presumably, the Web site you built for them) after sending them notice and giving them an opportunity to cure their breach of contract.
+ If you terminate their rights, that might well make them a copyright infringer if they continue to use the deliverables.
+ That in turn might give you ammunition to go after the owners personally, and not just the LLC, for the infringement (although that can be difficult to prove) [1].
+ The damages from copyright infringement might include the LLC's profits arising indirectly from infringement. (Of course, this assumes that the LLC has profits.)
In a famous case in the 1980s, the MGM Grand Hotel was found to have infringed the copyright of the musical Kismet by including much of the fourth act in the hotel's floor show. (MGM had a license, but not for that use.) When the dust settled, the damage award ended up being 2% of the hotel's overall profits --- including those from the casino [2].
+ If you can get, and record, a judgment against the LLC's owners personally, that might well [foul] up their credit score and make it difficult for them to borrow money.
+ Of course, all this requires money, and lots of it, to pay a lawyer and (at least one) expert witness on damages. If the dollar amount isn't that much, and if neither the LLC nor the individual owners have much by way of seizable assets, then it'll be difficult to get a lawyer to take the case on contingency.
+ And don't forget that no matter what you say are the facts, your client will invariably counterclaim that you did them wrong and should be liable to them. That, too, will cost money to litigate.
+ If you sue for copyright infringement and lose, you might be liable for the defendants' attorneys' fees -- while possibly not being able to recover your own fees even if you win.
Bottom line: Often it's better just to write off the debt, and next time get a deposit.
Check your contract:
+ The contract might provide that you have the power to terminate the deadbeat client's rights in the deliverables (presumably, the Web site you built for them) after sending them notice and giving them an opportunity to cure their breach of contract.
+ If you terminate their rights, that might well make them a copyright infringer if they continue to use the deliverables.
+ That in turn might give you ammunition to go after the owners personally, and not just the LLC, for the infringement (although that can be difficult to prove) [1].
+ The damages from copyright infringement might include the LLC's profits arising indirectly from infringement. (Of course, this assumes that the LLC has profits.)
In a famous case in the 1980s, the MGM Grand Hotel was found to have infringed the copyright of the musical Kismet by including much of the fourth act in the hotel's floor show. (MGM had a license, but not for that use.) When the dust settled, the damage award ended up being 2% of the hotel's overall profits --- including those from the casino [2].
+ If you can get, and record, a judgment against the LLC's owners personally, that might well [foul] up their credit score and make it difficult for them to borrow money.
+ Of course, all this requires money, and lots of it, to pay a lawyer and (at least one) expert witness on damages. If the dollar amount isn't that much, and if neither the LLC nor the individual owners have much by way of seizable assets, then it'll be difficult to get a lawyer to take the case on contingency.
+ And don't forget that no matter what you say are the facts, your client will invariably counterclaim that you did them wrong and should be liable to them. That, too, will cost money to litigate.
+ If you sue for copyright infringement and lose, you might be liable for the defendants' attorneys' fees -- while possibly not being able to recover your own fees even if you win.
Bottom line: Often it's better just to write off the debt, and next time get a deposit.
[1] https://www.whdlaw.com/Publications/WHD_Attorneywritesarticl...
[2] MGM Grand Hotel v. Frank Music Corp., http://cyber.law.harvard.edu/people/tfisher/IP/1989%20Frank%...