I think Poland has tried going after some of them. Recently hungarians passed some laws stating that communism is a criminal enterprise and revoked statutes of limitations for communist crimes. The new conservative hungarian constitution is worth reading.
Much more could be done worldwide, of course. The crimes of communists are so numerous and so appalling (think Katyn) that it boggles the mind. Whole nations enslaved by criminal gangs, economies bled dry, tens of millions imprisoned, slave labour, deportation of entire nationalities, dynamiting of thousands of churches, (muslims would be happy here) incredible oppression of conscience and corruption of generations... boggles the mind.
Indeed.
Well said.