The same is true for government efforts to nab murders, rapists, thieves, and arsonists. Depending on your view of government, you might or might not trust government to perform these tasks effectively. You might also believe that even these tasks are best left to the private sector, or, instead, you might believe that it's prudent to assign these tasks to government exclusively. Either way, none of these tasks would be considered criminal or illegitimate if carried out by private persons in the absence of government. No private citizen can ethically confiscate resources from others even if these resources will be used in ways that nearly everyone approves.
Examples are legion.
Of course not. Of course not. Nothing at all. Consider other activities currently pursued by government. It follows that government's efforts to redistribute wealth are illegitimate.