A parasite is one who feeds off a host and provides nothing in return. The host has no choice in the matter.

Every form of income redistribution falls into this category, including welfare (regular or corporate), Social Security, or other social programs. The issue is not charity, it is choice.

Someone who works for the government providing a service that is proper for government would not fall into the "parasite" category, although he is paid with tax money. A soldier, or policeman for example.

Someone who works for the government providing a service that, in a normal free society, would probably be provided privately, also does not fall into the "parasite" category, although he is paid with tax money. A postal worker, for example. Other government "jobs," like tax collector, one is not so inclined to be generous about.

The proper relationship between human beings is as a trader, value for value. When a dock worker buys a piece of software from Microsoft, that worker is the equal of Bill Gates, despite the huge difference in wealth. It is normal for a working class American to consider himself just as good as the richest man in America. We are so used to this in our country that I don't think most people realize what a novelty this is in history. We have wealth in this country, but except for a few fossilized society holdouts, we don't have "classes."

This is oversimplified, of course, but the basic philosophical and political principles are clear enough and one should be able to derive the rest easily on a case-by-case basis.