Bernie Madoff's pitch to his investors, for decades: He offered high and consistent returns. The reason those investors are now getting sued: He offered high and consistent returns. Believing his sales pitch was criminally idiotic!

The trustee for the defrauded investors found that $6 billion was pulled out of Madoff's funds in the three months before the fraud was exposed. Now he's suing to get all that money back from the lucky investors that pulled their money out. One might say: "Those were the smart ones, right?" Yea smart and criminal:

Both lawsuits were filed in Federal Bankruptcy Court in Manhattan. And both assert that the defendants, as professional investors, should have realized that their profits were too high and too consistent - and Mr. Madoff's paperwork and procedures were too sloppy - to be legitimate.

So basically if you were professional enough to say "Damn I better grab this here money quick," then you were also professional enough to know that the whole thing had to be a fraud. Winners lose!
[NYT]