weird question.cant really compare them if you dont say what kind of power.menpower?political?economic?also its sometimes hard to to tell the difference,because some organisations started as political("terrorist") and developed into oc(some say colombian groups are an example). most "terrorist" groups are making money with drug trade,illegal taxes etc... ..
Secrets are what Criminal organizations can not do better then terrorist organizations example mafia families in New York tell other families who members are.
In Ireland we have such power play refer to Criminal Action Force thread members of CAF unlike other places are not well known at all or their structure.
The CAF full membership is not known ether secrets seems the key to their success when they kill people or bomb places.
So seems CAF keeps secrets better then other Criminal gangs.