Certainly that is the intention for most social programs, but many fail to live up to their intention. Take Welfare for example. Obviously the intent is prevent folks from becoming destitute and stricken with lethal poverty. Welfare has achieved this but due to the tons of loopholes lots of folks abuse the system and are freeloading on our goodwill. The solution isn't necessarily to end Welfare, but at the same time we probably shouldn't increase Welfare without revamping the system to eliminate fraud.

Police do not prevent crime. They investigate crimes, identify and arrest suspects, and feed the criminal justice system. The threat of punishment is what prevents crime, not being caught by a policeman that summarily let's you go. Do you really think a car thief would stop stealing cars if we eliminated jails and just put more police on patrol? The only ounce of truth to your argument is that improving the likelihood of getting caught probably does decrease crime. Simply adding police does not result in linear gains on this end though. Look at the UK. There are more security/police cameras there than anywhere, yet they still have plenty of criminals.

You bandy the word neo-con about pretty loosely. Lots of folks, Democrats included, would like to see government spending decrease. To circle back to Welfare for a moment, I would prefer to teach people how to fish rather than giving them a fish. Obviously giving them shelter, clothing, and food is necessary for some time, but the goal should be to make people self reliant and responsible. The current Welfare system does little to improve a person's situation and is more focused on preventing it from declining. A truly progressive society would try to lift up the downtrodden, help them a get a job and become a productive worker in society. That's why so many people hate government programs. Their heart is in the right place, but they fail miserably where the rubber meets the road. Much of this disconnect is due to the massive, bloated size of the government. In an organization the size of the government the potential for abuses, fraud, and mistakes is more likely than a smaller more accountable government. Ultimately I think most folks that are critical of government spending, Republicans, neo-cons, Democrats, Independents, are really upset that there is no real accountability in government anymore. Some of the public faces change from time to time, but the bureaucracy is so mammoth it is virtually unaccountable. Consequently things that are broken never get fixed. Increasing spending on a broken system only loses us all more money and doesn't fix the problem

Madoff didn't play in a regulatory vacuum. He played in a highly regulated world where the regulators failed to do their duty. Madoff's firm was reported to the SEC back as early as 1999 but the regulators did nothing. Yeah, let's give them MORE control. The government NEVER let's us down.

There is, indeed little to no evidence that the modern tools (e.g. large scale databases or CCTV networks) actually help prevent crime which is, after all the goal.

Therein lies the disconnect between intention and results. The duty of police officers is to enforce and uphold the law, not prevent crime. The law itself, or more specifically the penalty for breaking the law, prevents crime. If an officer witnesses a crime in progress then they have the rare opportunity to prevent a crime. Mil tech that helps officers "prevent crime" really just helps them erode civil liberties one little bite at a time.