The traditional Illuminati were an Enlightenment society in Bavarian Germany based on Enlightenment thought. There is substantial thinking that the organization was based upon Freemasonry. There are some similarities, however Freemasonry does not involve itself in political matters, although a number of historic leaders have been Freemasons. The traditional Illuminati presumably were the power behind a number of political leaders and on occasion even plotted to overthrow them. The true Illuminati were outlawed in 1785.
There have been rumors, and several modern writers have insisted that the Illuminati still exist; that they are in control of a number of governments, and operate only in the shadows. Presumably, they have targeted several Presidents of the United States. Several modern fraternal groups claim to be the modern illuminati. There is no concrete evidence of such a group, only conjecture. The belief in a modern Illuminati plays well for those prone to conspiracy theories; for those of us more cynical, they do not exist and have no leader.
A man named Adam Weishapt formed the group in 1776. The group which has long since been outlawed I believe to have been an attempt to go public by the unseen Illuminati who are everywhere and in control of nearly all things.
It can only be postulated as to who the members are and who leads them (its not like they have a roster posted). Names which some have linked to the Illuminati are: Rothschild, Rockefeller, Bauer, Kennedy, Cavendish, Bush, McDonald, Roosevelt, and many other names of prestige. Some modern faces which come to mind are David Rockefeller, George Bush Sr., Henry Kissenger, Donald Rumsfeld, Dick Cheyney, Bill Clinton, Al Gore, Tony Blair, The Queen of England, and others further away from the spotlight.
Some say that secret organizations like The Freemasons, The Skull & Bones Society, The Bilderberg Group, Bohemian Grove and not-so-secret organizations such as the Trilateral Commosion and the Council on Foreign Relations are all simply outlets for the Illuminati.
When attempting to spot out members of this shadow society, look for people who belong to these secret fraternities, people who own or are in charge of large corporations, people who have very powerful friends and connections, people who are considered royalty or the elite as well as those connected closely to politics, media organizations, or those whose policies would be considered "globalistic" and rituals that are ancient in nature. You find someone who meets all of these conditions, and I could almost guarentee you have found a member of the Illuminati.
It is hard to say who their leader is. Some have suggested that the most poweful member is none other than the Queen of England. I myself believe that their true leader is divine. The common symbol of the Illuminati is the owl, the same symbol as the Goddess Ishtar (who is the same as the deity Semiramis, Queen of Babylon). Those who attend meetings at Bohemian Grove are said to prey to their "Mother Goddess" who is represented as a gigantic owl. There are many who associate the Illuminati with Satanism. The Christians believe that the Earth is "the Devil's playground" and I take that literally, believing that this deity dwells within Earth, and it is the Illuminati's role to carry out his command.