To conspire:
a : to join in a secret agreement to do an unlawful or wrongful act or an act which becomes unlawful as a result of the secret agreement
b : to act in harmony toward a common end.
It is in it self interesting that such condemnation has been associated with one concept, i,e. to act in harmony (although in secret) toward a common end.
Looking at the revelations related to the financial meltdown, the words bank secrecy (or bank privacy) even secrecy jurisdictions, take on some very familiar connotations.
Conspiracy Phobia
Some historical quotes