Consider the possibility of blackballing anybody who continues to be involved. Would that mean blackballing people who continue to work for government contract

Consider the possibility of blackballing anybody who continues to be involved. Would that mean blackballing people who continue to work for government contractors as well? Possibly. I'd say that is left up to the individual implementor. We don't need to all literally agree on a list of individuals to blackball. A general trend across some subset of the community would do just fine. Some people may take it to the extreme, some may only dissociate from a narrowly defined group of people. This sort of social tension, or pressure, doesn't need to be engineered with exacting precision. A respected professor here, an influential ex-boss there, one of your college buddies that you might consider asking for a recommendation one day... all can contribute to this ostracism in their own way.