Many ask whether one should milk the cow or not?
If the King has to protect the country and maintain law and order, he must collect the tax in such a way that it does not hurt the citizen and the citizen has enough for himself, while the king gets a share that will help him sustain.
This is explained with the example of a cowherd in Mahabharata which is interesting.
Milking the cow. Mahabharata, Shanti Parva, 88.4
madhudoham duhedrARASraM bhramarA iva pAdapam, vatsApekSI duheccaiva stanANca na vikuTTayet
A king should collect tax from citizens just like a bee gathers the nectar without harming the flower or the plant, and just like a Gopäl/ cowherd, who milks the cow while leaving sufficiently for the calf and without harming the udders.
Interesting to note that the King is advised to collect the tax. A King cannot do without collecting tax. He must collect tax in return to the service of maintaining law and order. Similarly, a cowherd must collect milk for serving Krsna in return to his service to the cow of caring for it.