It varies within a state, too.
One of the most common means of being disbarred pretty much anywhere is stealing from a client fund.
, long time no see!
Yeah, in Illinois the most common way for a lawyer to get disbarred is to steal from client funds. I don't think that's the easiest way (killing a judge in open court would probably top that list), but it is certainly the most common. Filing false pleadings might get one's ticket pulled. Engaging in criminal activities is another way to get booted (I was involved in a case, a long time ago, involving a bunch of lawyers who were part of a staged-accident fraud ring: those lawyers were either disbarred or voluntarily surrendered their licenses). Generally, engaging in activities or acting in a manner that conflicts with a lawyer's ethical and legal obligations can be grounds for discipline.