Westmeyer v. Flynn,  2008 WL 2152498 (Ill.App., 1st Dist., May 20, 2008). Courtesy of famed Chicago bankruptcy lawyer Steve Jakubowski, this decision  by the Appellate Court of Illinois, First District, Second Division, read opinion here, determined that Delaware law would recognize the concept of piercing the corporate veil in the context of an LLC. However, the 2 or 3 Delaware cases cited by the court are not directly on point in my view. Curiously, the court relies for its conclusion more heavily on opinions by the courts of other states applying Delaware law.  I think that a more nuanced approach is necessary  before one commences a wholesale application to the LLC context of piercing the corporate veil. As we have discussed on these pages frequently, not all the "conventional corporate analyses are automatically subject to being imposed onto the separate LLC framework."
See generally, Donald Wolfe and Michael Pittenger, Delaware Corporate and Commercial Practice in the Delaware Court of Chancery at Section 2.03[b][1][iii] (2008)(discussing  the concept of piercing the corporate veil generally as applied to corporations).