What would be some concrete examples found in todays society that demonstrate Macbeth to be as pertinent today as when it was originally...

Just look at any state-induced acts of terrorism sponsored
by a totalitarian government.  Just as Macbeth has his political enemies murdered
(Banquo, Macduff's wife and child), so too have despots killed and taken hostage
political enemies of the state.  Macbeth does not commit the murders himself, but he
sponsors them.  Most political "hits" are managed the same way.  Macbeth represents a
very modern, Machiavellian leader: vindictive, violent, controlling, and
paranoid.

Look at how some of the descriptions of the
following despots and autocrats:

Vladimir
Putin: "As president he gained a reputation as a clever and ruthless
political operator with a hunger for Russian power and not too much concern for the
niceties of democracy or diplomacy."

Kim
Jong-il: "the North Korean system became even more centralized and
autocratic under Kim Jong-il than it had been under his father. Although Kim Il-sung
required his ministers to be loyal to him, he nonetheless sought their advice in
decision-making; Kim Jong-il demands absolute obedience and agreement, and views any
deviation from his thinking as a sign of disloyalty. According to Hwang, Kim Jong-il
personally directs even minor details of state affairs, such as the size of houses for
party secretaries and the delivery of gifts to his
subordinates."

Saddam Hussein:
"On 5 November 2006, he was convicted of charges related to the 1982 killing of 148
Iraqi Shi'ites convicted of planning an assassination attempt against him, and was
sentenced to death by hanging."