I made the assumption (you know what that means) that people understood what a control system cyber incident was when I wrote Friday's blog on the BP oil spill. The following is a response from a technology writer about the blog: “Yeah, the old BSOD (blue screen of death), eh? We wrote about this last week”. A control system cyber incident as defined by NIST is electronic communications between systems that affects Confidentiality, Integrity, or Availability. BSOD in the ICS world happens all too frequently, but is not by itself a control system cyber incident.