A provocateur is someone who is in place to entice people in a group to take certain actions that would be detrimental to their cause, or otherwise beneficial to and outside and competing cause. In this case, the provocateurs were aiming for criminal actions. A probe is in place more as a means of collecting information and passing it to an outside handler. Also called a mole, these people can work their way into the higher levels of a large group and gain access to deeper information.