Another recent case is this tournament where Newbee got caught fixing matches and the tournament organizers dropped them right away.
It's obvious that most players wouldn't risk their career for a certain amount of money but there are other desperate players who are willing to put their career on the line.
An interesting case, but I would not compare events in such leagues with events in professional football leagues. Too different level of material interest, and hence the professional attitude to business. Look at the size of the prize money - they are ridiculous even for the top teams, it is not surprising that outsiders are trying at their own peril and risk to earn in other ways (I do not support them in this).