May 2011 is shaping up to be a bad month for the bad guys. Osama bin Laden, US enemy number one nabbed! Now the Europeans got their number one, Ratko Mladic.

He was arrested after 16 years in hiding in Serbia.

Just goes to show you can run, but you can`t hide forever.

Mladic may not be as globally well-known as bin Laden, but he is one of the most notorious war criminals of his era.

He was indicted in 1995 for the massacre of 8,000 Muslims.

Believe it or not, there`s an actual ranking of mass murderers courtesy of the

The usual suspects Hitler, Stalin, and Saddam Hussein made the list of the top 15 most killing killers.

None of them took the number one spot though.

That dubious honor went to China`s Mao Ze-Dong.

Some 70 million Chinese along with countless Tibetans and Mongolians died at his hands during his long and brutal reign.

Rwanda`s Jean Kambanda comes in at number 9 for his part in the 1994 genocide that killed 800,000 people in just 100 days.

Here`s a surprising one an American President made the list at number 15.

Harry Truman.

He authorized the drop of atomic bombs on Hiroshima and Nagasaki that killed about 120,000 people outright and fatally injured over 100,000 more.

But that was to end a war.

The guy in Serbia ruthlessly tried to wipe out a population of his own country.