“Warning for Russian citizens traveling internationally,” the Foreign Ministry bulletin said. “Recently, detentions of Russian citizens in various countries, at the request of American law enforcement, have become more frequent — with the goal of extradition and legal prosecution in the United States.” http://www.nytimes.com/2013/09/03/world/europe/russia-issues-travel-warning-about-united-states.html?ref=world   Citing examples in Costa Rica, the Dominican Republic, Lithuania and Spain, the Foreign Ministry said, “Experience shows that the judicial proceedings against those who were in fact kidnapped and taken to the U.S. are of a biased character, based on shaky evidence, and clearly tilted toward conviction.”

Extradition has frequently been a contentious issue between Russia and the United States, but the disagreements have been particularly sharp in recent months over the case of Edward J. Snowden, the former intelligence contractor who is wanted on criminal espionage charges but has been granted temporary asylum in Russia.
In response to the demands by the Obama administration for Mr. Snowden’s return, Russian officials have said the United States has routinely ignored extradition requests from Russia. Russia has also complained about the arrests of Russian citizens by the United States or by other countries at the Americans’ request.

There is no formal extradition treaty between Russia and the United States. Russian officials cited the lack of such an agreement as a main reason they could not forcibly return Mr. Snowden from the transit zone of Sheremetyevo Airport in Moscow, where he lived for more than a month until his temporary asylum request was approved.
Russia has often accused the United States of overstepping and potentially violating international law in its treatment of Russian citizens accused of crimes. It bridled over the handling of Viktor Bout, an international arms dealer who was arrested in Thailand in 2008 and was extradited to the United States, convicted in federal court and jailed in a federal prison.

The Foreign Ministry’s travel advisory mentioned Maksim Chukharayev, who was arrested in Costa Rica in May in an investigation into a huge money-laundering operation, and Dmitry Ustinov, arrested in April in Lithuania and accused of smuggling American-made night-vision goggles to Russia for resale.
The Foreign Ministry said Russian citizens could not expect to be treated fairly in the American justice system. “Russian embassies and consulates general logically give consular and legal help to Russians in trouble,” the Foreign Ministry said.
“However,” it added, “one should not count on a successful outcome in such cases.”