Don Johnson There one funny thing about the latest insider trading charges, which are against a former NASDAQ exec, Don Johnson.

(He's pleading guilty to making more than $600,000 insider trading. In one 2007 trade, Johnson made $175,000 by purchasing shares of United Therapeutics before successful trial results were announced for one of its drugs.)

His former job at NASDAQ: investigator of violations of the SEC's rules and regulations. From his bio (available for download by clicking here):

Don joined NASDAQ in 1989, initially as an analyst in the Market Surveillance department of NASDAQ’s parent company, the National Association of Securities Dealers (NASD). During his three-year tenure with the department, Don’s investigative work resulted in several high-profiled cases involving violations of the NASD’s and/or the Securities and Exchange Commission’s rules and regulations. Therulings in the cases ranged from substantial fines to permanent disbarment from the industry.

So the man who got people barred from the industry now risks a similar fate.

From the AP:

ALEXANDRIA, Va. (AP) — A former managing director of the NASDAQ Stock Market has pleaded guilty to stock fraud after admitting that he made more than $600,000 on insider trading.Fifty-six-year-old Donald L. Johnson of Ashburn, Va., was a managing director on NASDAQ's market intelligence desk until he retired in 2009.In a plea agreement Thursday in federal court in Alexandria, Johnson admitted to more than half a dozen trades in which he used non-public information to profit.In one 2007 trade, Johnson made $175,000 by purchasing shares of United Therapeutics before successful trial results were announced for one of its drugs.There is no indication that any of the companies did anything wrong by providing the non-public information to Johnson.He faces up to 20 years in prison.