Last week, I talked here and here about how insider trading was becoming more of a problem.

Now, as if on cue, we have the extraordinary story of two Morgan Stanley executives have been charged with insider trading in schemes involving their spouses.

That's on top of the Hong Kong couple who were last week accused by the US Securities and Exchange Commission in connection with insider trading in the shares of Dow Jones following a $5 billion bid by News Corp.

One of the accused, Randi Collotta, was a Morgan Stanley compliance officer. She pleaded guilty to charges that she tipped off her husband Christopher Collotta and a Florida broker, Marc Jurman, about Adobe Systems Inc.'s 2005 purchase of Macromedia Inc. and other deals. She and her hubby are lawyers.

"It's the equivalent of a CIA officer being indicted for selling defense secrets. You are the intelligence operation,'' Securities Law professor John Coffee told Bloomberg.

The connections here make it murkier and murkier, and they might tell us something about why insider trading is becoming more of a problem. It's not just pillow talk either, although that might have something to do with it, says The Times business editor James Harding.

"The extraordinary thing about insider trading is that more people don't do it. In the current frenzy of deal-making, the rewards are great, the opportunities are many and people privy to market-sensitive information are numerous."