Why would you want to pluralize Act? How many pieces of legislation do you want.
From terrorists. Period.
Or just by people who realize that Act refers to the legislation and not the behaviour of terrorists.
Hmmm, I see, still it reads odd to me, I took it as protection from the Terrorist Act not being able to understand why legislation was enacted against one act only of terrorists. Ok now I got it, it's an act against terrorist acts. I haven't been abusing substances either this evening.