Isn't the way Russian oligarchs pilfered Russian state assets equivalent to what a con man does?

The Russian Oligarchs are more comparable to the Robber Barons in late 19th Century America. Despite the similarities, however, there are important differences. The most important similarity is that both resulted from institutional and legal vacuums of which energetic, enterprising, unscrupulous men took advantage. 

In late 19th Century America, a national economy was beginning to emerge, most notably in the railroads and oil industry.  The U.S. economy was mainly local and regional. The Federal Government did not get much involved in the economy until a national economy began to emerge.  The Robber Barons (e.g. Rockefeller, Carnegie, Vanderbilt, Astor) took advantage of this anarchic environment and became fabulously wealthy.  Gradually, laws, regulations, and institutions to administer them emerged, and many of the Robber Barons morphed into philanthropists. 

With the collapse of the Soviet Union, a free market regime emerged suddenly in Russia out of a centralized command economy under the direction of the Communist Party.  Like the America of the late 19th Century,  this resulted in an anarchic economic environment.  Energetic, enterprising, unscrupulous men, for the most part taking advantage of connections from the Soviet era (Party, state, and criminal), were the only people positioned to benefit from this environment.  Like the American Robber Barons, they also became fabulously wealthy. 

What about the differences? First, there was a vibrant economy in late 19th Century America, but it was local and regional.  Anarchy existed only in the economic space of the emerging national economy.  Second, the Robber Barons had to create wealth. They had to build up the oil industry, build railroads, etc.  In the Soviet Union, the centralized command economy already encompassed the local and regional economies as well as the national economy.  The emerging oligarchs did not have to create wealth. They took advantage of the anarchic situation to capture existing assets.  

Some writers insist that this makes the Russian Oligarchs entirely different from the American Robber Barons so that it is not possible to compare them.  I disagree.  In both cases, bold, entrepreneurial, intelligent, ambitious, aggressive men were involved.  In both cases, the culprits moved into uncharted, chaotic situations, with little regard for the law.  True, the situation in Russia was more highly criminalized, and more mixed up with politics, and conflict was more widespread throughout society.  However, the similarities are significant. 

In the mid-1990s, a cartoon appeared depicting an imaginary conversation between Presidents Clinton and Yeltsin.  Frame 1 Yeltsin to Clinton: "You know, we are having serious problems with capitalism in our country.  Frame 2 Yeltsin continues: "You see, most of our capitalists are criminals." Frame 3: Clinton to Yeltsin: "Don't worry.  They will get power."  Frame 4: Clinton continues: "...  and they will change the laws." 

But it didn't happen quite that way in Russia. Soon after Vladimir Putin became President, he set out to curtail the power of the oligarchs.  At a meeting with the most powerful oligarchs, Putin told them that business was business and politics was politics. They should stick to business and stay out of politics.  Most of the oligarchs took Putin's warning to heart, but some did not.  As a result, Berezovsky, Gusinsky, and Nevzlin ended up in exile, and Khodorkovsky spent ten years in prison, after which he went into exile.  

The fusion of wealth and power in the hands of oligarchs thus became less of a threat to the development of the Russian state, yet blurred boundaries between politics and economics remain a serious problem.  In America, the excessive wealth of the Robber Barons grew to a point where they were perceived as a serious problem. Legislation and regulation reduced the seriousness of the problem.  Since, under the Soviet regime, economics and politics were inextricably fused together, unraveling them has been and continues to be a serious issue.