Conspiracy has been defined in the US as an agreement of two or more people to commit a crime, or to accomplish a legal end through illegal actions.
For example, planning to rob a bank (an illegal act) to raise money for charity (a legal end) remains a criminal conspiracy because the parties agreed to use illegal means to accomplish the end goal. A conspiracy does not need to have been planned in secret to meet the definition of the crime. One legal dictionary, law.com, provides this useful example on the application of conspiracy law to an everyday sales transaction tainted by corruption. It shows how the law can handle both the criminal and the civil need for justice.
When Fascism goes to sleep, it checks under the bed for Ron Paul!