SIGNIFICANCE:
1) Rudy is one of the most experienced prosecutors of the RICO Act, using it in at least 20 cases against organized crime families in New York and others.
2) The Racketeer Influenced and Corrupt Organizations (RICO) Act is a United States federal law that provides for extended criminal penalties and a civil cause of action for acts performed as part of an ongoing criminal organization. The RICO Act focuses specifically on racketeering and allows the leaders of a syndicate to be tried for the crimes they ordered others to do or assisted them in doing, closing a perceived loophole that allowed a person who instructed someone else to, for example, murder, to be exempt from the trial because they did not actually commit the crime personally.
That definition came from Wikipedia, but the following comes from https://www.law.cornell.edu/uscode/text/18/1961:
3) racketeering activity means
any act or threat involving murder
bribery, extortion, dealing in obscene matter,
obstruction of criminal investigations
tampering with a witness, victim, or an informant
trafficking in persons
laundering of monetary instruments
sexual exploitation of children