Trading on the NASDAQ, America's second-largest stock exchange, ground to a halt for some time today due to "technical issues".
Shortly after noon EDT, NASDAQ announced that its systems were experiencing problems and it suspended trading for over three hours.
An obvious question to ask is - was this a common-or-garden standard glitch or cock-up, or were hackers somehow responsible for the disrupting the world's largest electronic stock market?
It certainly would not be the first time that cybercriminals have turned their attention to stock exchanges.
For instance, two years ago, hackers launched a DDoS (distributed denial-of-service) attack against the Hong Kong stock exchange HKEx, causing trading to be affected for some hours.
And way back in February 2006, computer systems at RTS was hit by a mass-mailing virus which generated so much internet traffic that the Russian stock exchange felt forced to suspend trading until the outbreak was contained. There is no reason, in that instance, however, to believe that the stock exchange was deliberately targeted.
One site that was deliberately targeted, however, was NASDAQ itself - who called in the FBI in early 2011 to investigate a hack of its "Directors Desk" web-based application used by thousands of directors worldwide, including many Fortune 500 companies.
Most recently, just last month, hackers hit the NASDAQ's community forum, compromising email addresses and passwords.
Although that hack didn't impact trading in any way, there were concerns at the time that that the hackers could have accessed sensitive information.
Is this latest problem at NASDAQ the work of hackers? At the moment, we simply don't know. The outage could have been the result of sloppy programming, computer error or some other technical fault - or it may be the case that malicious hackers had a hand in the proceedings.
One thing's for certain. There are hackers out there with a vested interest in manipulating stock prices for financial gain or disrupting and sabotagingthe United States economy. Strong security systems and safeguards need to be in place to ensure that the possibility of such attacks being successful are kept to a minimum.