Everytime we want to prepare an essay, thesis, discussion, etc., we need a hypothesis. It's the basis, it's what keeps our arugments together, the reason, they are not completely over the top. In case of essays, we normally either agree or disagree with either the statement from the topic or what it indicates.
Here, our starting point is preventive vigilance. We need to think if it's good for the people, not good for the people or maybe, we would like to show both sides of the coin and say that:
We cannot disagree with a fact that preventive vigilance seems to be the answer to better prevention of corruption inside governmental offices. We cannot forget though, that there are more then plenty reasons to be careful with any kind of a system such as this.
... this way, we know that yes, indeed - we agree that it's necessary, but we also point out that it might be a bit dangerous and should be overseen well. Why? Because any kind of prevention is, usually, associated with some kind of invigilation.
At the end of the line, it is always your decision to decide whether you will choose to opt for/against a statement or stand somewhere in the middle.