^Laughing at the irony.
Anyway, something tells me this is an actual act of terrorism.
Following standard profiling, This was a very meticulous attack; calculated and conspired. There was little sloppiness in its execution. The intent wasn't to simply kill people for amusement or pleasure (like the random slew of shootings and stabbings as of late), but to make a general statement. Political, religious, social--pick one.
Who, why and what are completely speculative at this moment.
Either way, it is pretty horrific.