The Washington Post reported over the weekend that the CIA had warned U.S. utilities of the possibility of attacks, or threats with extortion demands, via the internet. At a conference in New Orleans attended by security officials from governments, utilities, and companies such as Chevron Corp. (NYSE: CVX) and BP (NYSE: BP), a cybersecurity analyst broke with CIA disclosure polices to detail several recent cyber intrusions outside the United States, one case resulting in a power outage that affected several cities.

Increasingly sophisticated intrusions into corporate computer systems have cost companies worldwide more than $20 billion each year, according to some estimates. And extortion is a growing threat, with attackers radically increasing their take from online gambling sites, e-commerce sites, and banks, which pay up to prevent their sites from being shut down and to avoid public knowledge their sites have been hacked.

With the rising tide of cyber attacks on the infrastructure over the past year or so, and the vulnerability of the power grid, transportation systems, and big banks becoming increasingly clear, investors have to wonder how secure the exchanges are from extortion or efforts to manipulate the markets by individuals or organized groups. The London Stock Exchange suffered a cyber attack this past June. Such attacks frequently originate from overseas, sometimes supported by foreign governments, and perpetrators can be next to impossible to track down and bring to justice.