As background to this question, we recommend you read the material above on Tucker's views of the four capitalist monopolies. The material below is supplemental, and presupposes the reader is already familiar with Tucker's analysis.

The land monopoly. According to Proudhon, in What is Property?, contrasted property based on "proper or individual possession" with modern property, in which an absentee owner of property asserts "the right to use it by his neighbor's labour..."

The money monopoly. The authors of the Anarchist FAQ sum up the effects of the money monopoly quite succinctly:

The credit monopoly, by which the state controls who can and cannot loan money, reduces the ability of working class people to create their own alternatives to capitalism. By charging high amounts of interest on loans (which is possible only because competition is restricted) few people can afford to create co-operatives or one-person firms. In addition, having to repay loans at high interest to capitalist banks ensures that co-operatives often have to undermine their own principles by having to employ wage labour to make ends meet....

So the credit monopoly, by artificially restricting the option to work for ourselves, ensures we work for a boss. (B3 pp. 3-4)

To fully grasp how crippling the money monopoly is, we have to take a look at the alternative.

The patent monopoly. [GATT, patent control, etc.

In addition to the four monopolies listed by Tucker, there other forms of privilege even in Tucker's day that he neglected to mention. [Primitive accumulation, transportation]

Rise of Progressive welfare/regulatory state, MI complex, Wagner act, etc.