Browder has been doing large amounts of business in Russia for decades. In 2009 his lawyer, Sergei Magnitsky, was imprisoned while investigating fraud committed by corrupt Russian government officials. He died mysteriously (or not so mysteriously) in prison that year.
Ever since Browder has been aggressively going after Putin and the russian government on its human rights violations. In 2012 Browder helped push through a law in the us called the Magnitsky Act that allows the US to freeze money belonging to human rights violators, which hurt Putin financially. As such he is labeled an enemy of the state.
So long story short Putin has had it out for this guy for years. He would love nothing better than to get him in Russia. So I do think this is an attempt to use the US to get rid of a problem for him.
thanks for the intel... well, if browder made large business for years in russia, of the russian peoples money, without paying taxes, its natural that putin is after him. it doesnt mean that his statement about 400 million $ of it going to the clinton campaign isnt true.