Obtaining visas is a big hurdle for many Russians doing business in Europe.Medvedev bristled at any criticism of Russia â¿¿ in particular the Davos report on the risks ahead for its economy, saying its scenarios for Russia's future are "not realistic" and insisting that the economy wouldn't collapse if oil and gas prices sink. High energy prices have been key to Russia's economic successes over the past decade and have given President Vladimir Putin extra weight in global affairs. The Davos report warned that Russia needs "significant changes in its domestic institutional environment" to keep the economy growing. Alexei Kudrin, a former longtime Russian finance minister, called the report "a serious lesson, a serious signal to the powers in Russia." Others talking about Russia at Davos predicted that the country's leadership is unlikely to change on its own. More likely, they said, is bottom-up reform, stemming from street protests or from a growing middle class that wants more accountable politicians. The son of jailed Russian tycoon Mikhail Khodorkovsky issued an appeal to Davos participants to press the Russian delegation to eradicate corruption. "All Russians are proud that our country is playing a more significant role in world affairs, obtaining accession to the WTO and winning the right to host the 2014 Olympics," Pavel Khodorkovsky wrote. "But as long as Putin's authoritarian regime doesn't stop suffocating independent political activity, limiting the work of NGOs, taking heartless measures like the ban on adoption of Russian children by U.S. parents ... Russia will never take the place it deserves as one of the leaders of the world." Russia's role as Olympic host got another black eye after a top Russian crime lord was gunned down last week in Moscow in what police described as a war between two powerful mobs over lucrative construction projects, allegedly including ones for the 2014 Sochi games.