Yep....but more precisely, you aren't allowed to use the "T" word if the acts occur on American soil. Anywhere else, and the use of the "T" word is almost mandatory.
A plane gets blown out of the sky over NY on Veterans' Day? ...The only "T" word used that day was "turbulence."
An Arab gunmen kills several people at LAX on Independence Day? ...No "T" word. It was just some "deranged nut."
Regarding the NJ shootings, terrorism is on the minds of most thinking people, but on the lips on virtually no one.