Schooled in Scandal: What Makes Ukraine a Hotbed of Intrigue

POLTAVA, Ukraine — After four years of investigation by the German police, the F.B.I. and other crime-fighting agencies around the world, heavily armed security officers stormed an apartment in the central Ukrainian town of Poltava. After a brief exchange of gunfire, they captured their prey: the man suspected of leading a cybercrime gang accused of stealing more than $100 million.