In German, blitz means "lightning"; krieg means "war."
Blitzkrieg, "a violent surprise offensive," usually describes German tactics in WWII. The eight shattering months of nighttime bombardment of London by German forces was called simply the Blitz.
Today, it's a far milder word.
Blitz now describes an "intensive campaign or attack," as in this headline: "Blitz on Speeders Nabs Thousands." (Edmonton Journal News, April 7, 2010)
Of course, it also means rushing the quarterback, as illustrated here.