You don't have to something super bad to be labelled a felon. Simple drug possession, not selling but being caught with certain drugs or a certain amount, will result in felony charges. In fact, a majority of felons in Federal prisons are drug related, though that percentage is much lower in State prisons, where there are more violent offenders.

http://felonvoting.procon.org/view.resource.php?resourceID=0...