Followers of Milton Friedman would not privatize everything. Do not confuse the radical Ron Paul-types who want NO government and everything privatized with free-market economists. What free-market economists believe in is, IN GENERAL, the government should be limited and the market mostly free and most things privately-owned. In general, government should keep a hands-off policy and keep taxes low. However, there is obviously a limit to this, and the government plays a very important role in certain areas. For example, the Securities and Exchange Commission. I am not for government regulatory agencies at all when un-needed, but I understand that without the SEC, our financial markets would be in who-knows how much chaos. I understand the role of the Federal Reserve. I understand that things such as police, firefighting, etc...need to be publicly provided as when privatized they do not function correctly. And free-market economists understand that the environment needs protection too. But what the legislators need to take into account is to make sure they do not restrict people's freedoms or destroy industries through being over-zealous in protecting the environment.
No sensible free-market economist would just switch Social Security to being privatized. I do not believe SS should have ever been created in the first place, but it is here now, so it's to stay for the time being. Purely privatizing it would be silly, as the average citizen does not know how to play the stock market at all or invest; many professionals even make huge blunders in this.
But no one can deny that SS faces some big problems either. What free-market economists seek is to combine the benefits of privatization with the security of government for SS, so that SS could make a lot more money, but still remain secure for market crises and so forth.
Belief in the free-market and invisible hand are fine, as these have been proven to work, for the most part. But there are exceptions, for things such as the financial markets in particular, where the government plays a role when required. Things such as wealth redistribution, extensive government intervention and high-level government spending, price controls, protectionism, tariffs, subsidies, etc...in general, are wrong and bad for the economy. Inequality is necessary for the functioning of a free-market economy. There is nothing wrong with a lot of wealthy people being minted or a large level of inequality, as long as the standard of living for the middle-class is continuing to increase. This just means much wealth is being created and there is a lot of prosperity. No one is entitled to the wealth created by the wealthy folk. No where does it say we are all supposed to come out equal in the end. There is a problem when the middle-class is eroding or their growth in standard of living has slowed, or stopped, while many wealthy continue to form. Blaming the wealthy for this is not necessarily correct, but it means there is a problem in the economy that must be fixed.