the last 100 years is pretty short. A mite farther back there are plenty of examples of notorious people. There are plenty of modern people from the last 20 years that might qualify. However looking at history I would have to say Nero. Ceasar Nero. He was a paranoid individual and had his mother and tutors killed. Was at least privy to, if not involved in the assination of claudius. This lead to him becoming ceasar.
In 64 AD, the great fire of rome (broke out among the shops of circus maximus) and killed thousands. It destoryed 2/3 of rome. Nero probably had something to do with the fire, used the fire to start the first persecutions of christians and to rebuild Rome to be even more opulent than it already was.
Domus Aurea – This structure was built on the ashes of a terrible fire that destroyed a large part of Rome in 64 A.D. Domus Aurea was built on the wishes of Nero, who was also probably responsible for the fire. During one of his famous ravings of omnipotence, the prince wanted a more majestic Rome with his enormous, new residence as the center of this newly-styled city. Inside this new palace there were buildings, gardens and a lake called "Stagnum Neronis". The palace was disproportionately large, but was in perfect harmony with the 35-meter high bronze statue of the prince that was sculpted and placed at the entrance to the Domus Aurea. The Domus Aurea has recently been opened to the public after years of restoration work.
Along with the rebuild Circus Maximus, this area became well known for the many bloody and viscious acts of entertainment. Thousands of people and animals were put do death in every way imaginable making the colleseum look like a walk in the park. This is a small numbe of things that he did or happened as a result of his influance. It is a period of time that the italiens are still trying to put behind them. It is not something that they like to talk about even today.