Drugs, prostitution, money laundering, violence and protection rackets. I really don't think that we should have a problem with the removal of such people from our society.
The devil is in the details. I think that most people would happen to agree, but I don't approve of e.g. capital punishment or arresting based on being associated with a gang involved in criminal activity. These kinds of reactions don't just affect the current generation, they affect that generation's kids. Only rehabilitation of the parents is likely to seriously improve their lives, IMHO.