Sniping is an offensive weapon, not a defensive one. You can't post snipers everwhere and shoot everybody, that is what clusterbombs are for. When the Palis use children and women pretending to be pregnant like the suicide bomber before last that got in using an ambulance who do you shoot? The Jews are trying to not kill civilians, the Arabs are. That is the entire hinge point on this conflict. The moment that the Jews make the decision that civilian casualties in the Arab ranks are necessary to stop this and worth doing, Palestine ceases to exist.
I was think along the line of deploying them to maintain control outdoor movement of people so that anybody who is doing something suspicious will be taken out. This obviously does not stop all infiltrations. But we will have less people attacking and less people in the street in general. I doubt that, if they know that there are snipers everywhere, they do not go out unless it is absolutely necessary. I thought this is a way of squeezing them harder since Israel cannot exercise more drastic and logical option.