Former Credit Suisse First Boston(NYSE: CSR) investment banking star Frank Quattrone isn't going down without a fight.

After being placed on administrative leave early last month, and resigning in full on Tuesday, Quattrone now faces a host of charges filed by the National Association of Securities Dealers. He's standing his ground, though, and defending himself against the complaints.

The NASD alleges Quattrone pressured analysts to say good things about companies with which CSFB had banking business. This breach of the so-called "Chinese Wall" separating a firm's banking from its analysis is particularly poignant in Quattrone's case.

Not only were there apparent breaches, but the actual separation of the two is questionable, since Quattrone oversaw both groups -- the tech research team and the bankers. Quattrone was the wall, and from the looks of it, a very flimsy one.

In addition to those charges, the NASD alleges Quattrone illegally allocated shares in hot IPOs to executives ("Friends of Frank") who could send banking business his way.

Finally, the NASD charges Quattrone failed to cooperate with its investigation into whether he instructed underlings to "clean up" files following knowledge of impending investigations. He was to show up for testimony on the matter last week, but failed to do so.

Quattrone's lawyers have an interesting first defense. In a released statement, Howard Heiss said, "The NASD charges are completely without merit and represent an unprecedented attempt to take punitive action against an individual for conduct that was legal at the time and widespread throughout the industry." Doesn't that seem like the "But they did it, too!" defense?

And according to spokesman Bob Chlopak, "[Quattrone] firmly believes he did nothing wrong." Well, OK. To each his own delusions.

If convicted, Quattrone faces fines, censure, suspension, and a possible lifetime ban on ever working in the securities industry again. He could also be forced to give back the moolah he made off the illegal activities.