I dont think thats gonna fly with public opinion, even in a militaristic society as the US. "Oh no, they defaced my facebook page, lets launch a nuclear attack(*)"
(*) attacking active nuclear installations, is a nuclear attack IMO.
Anyway, I dont think they will do anything to Iran before having toppled Assad in Syria. Thats clearly where the propaganda is focusing on now.
I think a major cyber attack such as bringing down power stations, or even leading to their destruction (especially in the case of nuclear power stations) by overriding control systems, or bringing down the electricity network or bringing down Air traffic control, would certainly fly with public opinion.