At Pro Tour Dragons of Tarkir Steven Speck was caught presenting a 53 card card with the seven cards that he wanted in his opening hand tucked somewhere out of sight. This is a clear and blatant cheat, and as such the investigation of Speck was open and shut.
Speck was given a three year ban for his cheat, which by many accounts is too light.
Known cheater Alex Bertoncini famously came off a three-year ban and immediately started cheating again. This makes one wonder- how likely is it that somebody who commits a cheat heinous enough to deserve a three year ban would ever come back and play a straight game?
Lifetime bans sound extreme, but at the end of the day playing Magic isn't a right. Minimally, I support the camp that says that three years isn't a long enough suspension, especially when you consider the thousands of dollars of prizes that were more or less taken out of the pockets of honest players.