This seems timely

Watergate Special Prosecutor Leon Jaworski in The Right and the Power (1976):

In criminal law the rule is well recognized that one who learns of an ongoing criminal conspiracy and casts his lot with the conspirators becomes a member of the conspiracy. Once the existence of a conspiracy is shown, slight evidence may be sufficient to connect a defendant with it. But one odes not become a member of a conspiracy simply because of receiving information regarding its nature and scope; he must have information regarding its nature and scope; he must have what the courts describe as a "stake in the success of the venture." He "must in some sense promote the venture himself, make it his own, have a stake in its outcome. …" Although one member of the conspiracy must commit a overt act, it is not necessary that every conspirator do so.