Regulators frown on free communications between knowledgeable company executives and information-hungry investors. LinkedIn offers "compliance" tools, but those tools amount to letting the fox electronically monitor the henhouse. Hedgies surely realize this, and will see LinkedIn's lax policies as a selling point. (Other firms which connect investors with company insiders have, at some expense, created systems which allow the experts' employers, not just the investment firms, to monitor contacts.)

If it gets in trouble, LinkedIn will likely plea that it didn't know how its networking site was being used — the standard we're-just-a-platform dodge. But it will be hard to claim that for two reasons. First, LinkedIn is touting the account managers it's providing who will actively help traders use the service. Second, CEO Dan Nye previously worked at Advent Software, a company which provides portfolio-management software to Wall Street firms. It's not like he's unfamiliar with the SEC's disclosure and monitoring requirements. Rather, one has to think he knows just how expensive complying with those rules are, and that rejiggering LinkedIn's software to obey them will make LinkedIn Research a nonstarter.

It's not a stretch to imagine how an ambitious government prosecutor could make a case for LinkedIn aiding and abetting insider trading. The law doesn't even require that money change hands; exchanging inside information for a thumbs-up reference on LinkedIn could very well qualify as a breach of the rules.

But that assumes anyone in Washington or New York is paying attention. Unlikely, given the mortgage mess. LinkedIn will likely go public on the basis of its hedge fund-juiced revenues long before an overtaxed SEC gets around to looking at how, exactly, the avaricious traders of Greenwich are getting their information.