It could mean anything as simple as the mass disruption of telecommunications networks; the manipulation of data in critical systems, for example, at Treasury Board or Bank of Canada; or the remote manipulation of SCADA or process control systems around either electricity delivery networks or things such as nuclear power plants. It's both near physical effects, in other words, where you're touching infrastructure, or it's the manipulation of information such as to make that information unreliable or to foster a failure of the systems through not being able to rely on the input being given.
On November 20th, 2014. See this statement in context.