Other than doing that by DOS attack or sabotage you'd probably need a court order and a local enforcement able and willing to enforce it. If the guys have servers in Denmark, Costa Rica, or Holland, etc, you'd need to get that legal and law enforcement systems involved, which would probably mean, at the minimum, legal representation of some kind in those countries, as well as a lot of patience. Witness the dudes from Pir% Ba%. They probably move their ip address and connections from place to place routinely.