If it looked like the beginning of the Digital Pearl Harbor scenario pundits have been predicting for more than a decade, you probably were in good company. Earlier Wednesday, the New York Stock Exchange suddenly halted all trading, citing unexplained technical problems, while United Airlines grounded all flights, and The Wall Street Journal website returned a 504 error indicating there was something seriously wrong with the news organization's servers.

Within a couple of hours, operations at both United and WSJ.com were back to normal. Airline officials reportedly cited a network connectivity issue resulting from a faulty router and said they were working to get flights back on schedule. The WSJ, meanwhile, redirected visitors to a temporary site before eventually restoring the regular one. Officials at the news organization have yet to comment on the cause of the outage.

By that point, there was already good reason to suspect the outages weren't the work of malicious hackers, but that didn't stop officials at the White House, the Department of Homeland Security, and the NYSE from issuing statements saying the outages were not part of some sort of cyber attack. Shortly thereafter, at a little after 3pm New York time, the exchange finally reopened, nearly four hours after all trades had been suddenly halted. News organizations citing unnamed sources said the unprecedented outage was the result of a faulty software update that was installed before trading began Wednesday morning.

While it's impossible to rule out the possibility of a catastrophic hack attack that wipes out key parts of the critical infrastructure, it's also important to remember networks go down all the time. Occasionally two or even three very public networks experience problems at the same time, as appeared to be the case Wednesday.