This means that already existing conspiracies must be infiltrated. Other than entrapment, the only other defense available to the defendant is complete and total withdrawal. The standard is high. The defendant has to show their complete and total withdrawal that they tried to notify or tip off authorities, felt guilty about their own involvement, and took active steps to thwart the conspiracy. The last thing to remember about conspiracies is that, in this area, the law doesn't recognize anything sacrosanct about the husband-wife relationship.
All bets are off in terms of privileged relationships.
A skilled investigator can use this to obtain important information and witnesses. Having him invest further 7. Sending him after more money 8. Playing him at the big store 9. Getting him out of the way 10.