Since Jack wasn't willing to let go of those that had attacked him, he had tracked their location, and found them. After finding them, he did his investigation, and found out that none of them had any good records on them.
And for that reason, even though he knew that these people were used by the Zigo government, he didn't care. Since none of them was a good person anyway, then, if they were let go, then they would definitely continue with what they were doing before.
Who knew if they were going to attack him another time? That was something that he wasn't ready to deal with. He himself was busy, and wasn't going to counter attack every now and then.
So, using his computer mastery skills, he easily hacked into Zigo defense system, and managed to take over the missile control system. Without even giving time for the defense system to react, he launched a medium range ballistic missile.
