I talked to a lawyer about this and the feedback I received was while technically they might be able to sue to try and receive compensation even from your personal assets if you are a single-member LLC as long as you can show you were acting in good faith and as an agent of the company (i.e. you didn't personally guarantee the work and sign your name instead of the company's and you maintain distinct records and finances for the business), then it is unlikely to get approved in a court of law.

So an example here might be that you were working for a client and work wasn't fully completed on time. You made a good faith effort to get the work done, so while the company you were working for might be entitled to compensation from your LLC they can't come after your house.

Finally, let me caveat all this by saying that the standards for "piercing the corporate veil" vary by state and as always you should consult with a lawyer before making a final determination. Also, another work around is to form a multi-member LLC and hold formal annual meetings. This is normally enough for most states to consider the LLC as a separate distinct entity and prevent piercing of the corporate veil.